Google's Nexus devices are meant to be the Holy Grail of Android technology - pure representations of the platform that show just how good its user experience can be. With its new Nexus 4 phone, Google offers its best effort to date and its most aggressive attempt to upend the smartphone market.

The Nexus 4's most noteworthy feature may well be the phone's pricing and sales model: The device will be sold unlocked and contract-free directly from Google: £239 for an 8GB version or £279 for a 16GB phone.

This may sound like a normal price, but it's actually extremely low. While most comparable smartphones are sold for a few hundre pounds, that's only because they're subsidized by carriers - in other words, the carriers cut the price in exchange for a guarantee that you'll subscribe to their services for a full two years. Most phones of this calibre would cost more like £500 if bought in a similar unlocked and unsubsidised manner.

Buying the phone outright means you wholly own the device and are under no obligation to anyone. As a result, you can choose to use the phone with any compatible provider - including prepaid service providers, which often offer the same basic service you're used to at a fraction of the cost - and can switch providers at any time with no penalties or fees.

[See also: Google Nexus 10 tablet review]
[Slideshow: Hands on with Google's Nexus 10 tablet]

(The Nexus 4 will be offered through a more traditional sales model as well - but most consumers would fare better in the long run by choosing the unlocked model.)

So pricing aside, what's the Nexus 4 actually like to use? I've spent the past week using the phone in place of my own personal device. Here's what I've found.

Body and display

The Nexus 4 is manufactured by LG, but don't let that fool you: This is without a doubt a Google phone. Google's Android engineers worked closely with LG on every facet of the device's design, and the company's influence clearly shines through - so much so that at a glance, the phone actually looks quite similar to last year's Galaxy Nexus device.

While the general design language remains consistent, though, the Nexus 4 is anything but an incremental upgrade - and that's immediately apparent the minute you pick up the device. The Nexus 4 feels sleek, solid and substantial. It's a luxurious piece of hardware, with not a single flimsy or plasticky-feeling surface to be found.

The Nexus 4 is 133.9 x 68.7 x 9.1mm and 139g - almost exactly the same dimensions and weight as the Galaxy Nexus, despite its roomier display. Speaking of display, the Nexus 4 has a gorgeous 4.7in True HD IPS screen with 1280 x 768 resolution and 320ppi. The screen is among the best I've seen on a smartphone, rivaling the likes of HTC's One X and Apple's iPhone 5 for top honours. Colours are bold and brilliant, details are crisp and sharp, and even in bright outdoor lighting, the Nexus 4's screen remains impressively viewable.

Google Nexus series

(Incidentally, the contrast with the Galaxy Nexus in that regard is immense: When I hold the two phones side by side in direct or even indirect sunlight, the Nexus 4's display is easy to read while the Galaxy Nexus's screen is almost impossible to see. It's amazing how much difference a year can make.)

This isn't just any regular ol' glass, either: Google has introduced a new type of curving technique with the Nexus 4's display in which the screen is sloped subtly at its edges. The goal was to create a surface that matches the way you interact with the phone - swiping and gesturing side to side. That's a marked change in approach from past Nexus devices, which were curved to match the shape of your face.

It's a subtle yet important distinction: The physical act of moving my fingers on the Nexus 4's screen feels smoother and more natural than on any device I've used. By optimising the phone's form for touch over talk, Google is making a bold move - but one that very much matches the way our smartphone usage habits are evolving.

The Nexus 4's screen extends all the way to the sides of the phone's face, creating a large surface area on an otherwise reasonably sized device. The display is surrounded by a thin silver metal band that's most visible when you look at the phone from the side. The edge where the screen and the band meet is a pleasingly smooth curve that's not at all sharp to the touch - a demonstration of the attention to detail that went into this device.

Another impressive bit of detail, surprisingly enough, is on the phone's back: The Nexus 4's rear is a smooth and reflective glass plate with a crystallised design that appears to move as you tilt the phone. The effect is eye-catching and distinctive without being over the top; you actually don't even notice it until you're looking closely at the phone. One minor drawback: The glass does seem to pick up an inordinate amount of visible fingerprint smudges.

The bigger risk with this flourish, of course, is that glass is inherently prone to breaking. Google and LG have taken steps to reduce the risk of shatter, including using Gorilla Glass 2 on both the phone's front and back and implementing edging that extends ever so slightly past the rear glass's reach in order to help break a fall - but still, the more glass you have, the more risk you have of it cracking. If you have butterfingers, you may need to use a case or bumper in order to maintain peace of mind.

The Nexus 4 has a small LED indicator at the bottom of its face that alerts you to missed calls, new messages and other system events. As with other Android phones, you can customize exactly how and when the LED works by installing a third-party LED control utility.

Buttons, ports and charging

The perimeter of the Nexus 4 is taken up by a soft rubberised plastic material. On the left side of the phone is a silver metal volume rocker along with a tray for the micro-SIM card, which is locked shut and requires a small pin tool (included with the device) to open. The top of the phone has a 3.5mm headphone jack, and the right side houses a silver metal power button, which - to be nitpicky - is set back just a hair too far in the device and is consequently not always easy to press.

In terms of buttons, that's it: The Nexus 4, as you'd expect, utilises virtual on-screen buttons for the main Android functions (back, home and app-switching), matching the design standards introduced with Android 4.0 last year. Given the fact that this is the way current versions of the Android operating system are designed to be used, this setup creates a far more fluid and user-friendly approach than the dated button-reliant configurations some manufacturers continue to employ.

The Nexus 4 has a standard micro-USB port on its bottom, which doubles as an HDMI out-port. LG and Google have opted to go with a relatively new protocol known as SlimPort instead of the more typical MHL interface for the video-out functionality. The upside of that setup is that SlimPort adapters are able to charge the device while it's connected to a TV, monitor or projector; they're also able to connect via both HDMI and VGA. The downside is that you'll need a special SlimPort adapter in order to make any such connections.

The Nexus 4 supports wireless charging via the Qi charging standard. Google has shown off a futuristic-looking "charging orb" upon which you can simply set the phone to charge it; that accessory was not available for me to review, and it's not yet clear when it'll be available for purchase or how much it'll cost. The phone does also support standard micro-USB-based charging, though, and comes with a normal micro-USB-to-USB cable and wall adapter.

Connectivity and calling

The Nexus 4 is a GSM phone, which means that in the US it'll work on either AT&T's or T-Mobile's network (which are also the networks utilised by most prepaid carriers). That brings us to one sticking point with the phone: While it does support 4G-level data speeds, its network compatibility means it supports only HSPA+ connections - not the faster LTE connections that have become commonplace with many smartphones in the States.

That said, I found the Nexus 4's data speeds to be perfectly satisfactory while using the device on T-Mobile's HSPA+ network. I routinely clocked in near the 18Mbps mark when I checked my speeds using Ookla's application. The phone is capable of speeds as fast as 42Mbps, depending on your area and connection.

Google has described the Nexus 4's lack of LTE as a "tactical" decision, noting the limited availability of LTE outside of the U.S. along with the increased cost and decreased battery life the technology tends to deliver. So is the lack of LTE a deal-breaker? That's up to you to decide.

Google Nexus 4

Personally, in most typical day-to-day phone-based usage -- Web browsing, social media use and the like - I find it tough to tell the difference. (Some analyses have actually found T-Mobile's HSPA+ network to be comparable to or faster than LTE networks in parts of the country.) Remember, we aren't talking about 4G vs. 3G here; we're talking about 4G LTE vs. 4G HSPA+.

(You may also want to consider that owners of last year's 4G LTE Verizon Galaxy Nexus have found that the carrier-dependent configuration comes with some troubling caveats - namely, delayed upgrades and software interference - that directly clash with the "pure Google" promise of the Nexus brand. As someone who's used both a Verizon-bound Galaxy Nexus and an unlocked HSPA+ version of the phone, I've found the latter setup to provide a much better overall experience.)

In terms of actual phone calls, the Nexus 4 performed admirably in my tests. I could hear voices loud and clear - so loud, in fact, that I often had to turn the volume down on the phone - and people with whom I spoke reported being able to hear my voice fine as well.

The phone's external speaker is sufficiently loud, too, with more than enough volume to handle calls and music alike. When I tested the Nexus 4's speaker alongside the Galaxy Nexus's, audio played through the Nexus 4 was significantly louder and clearer-sounding with both phones at their maximum volume settings.

The Nexus 4 supports near-field communication (NFC) for contact-free sharing and services. Those services include the Google Wallet mobile payment system, which comes preloaded on the device.

The phone also supports Miracast, a new wireless display-sharing protocol. With the right adapter, Google says you can stream both audio and video directly from the Nexus 4 to any HDTV, with the TV mirroring everything on the phone. Be warned, though: Finding an adapter that works right now is easier said than done.

I tried setting up wireless display sharing with my TV using a NetGear Push2TV Wireless Display Adapter, which costs $60 and promises support for "Miracast-capable" devices. As I discovered, though, the product is limited only to "pre-standard compliant" Miracast devices (to NetGear's credit, that is in the fine print) and consequently doesn't work with the Nexus 4.

A full line of standard Miracast adapters is expected to become available soon. LG is also expected to start shipping TVs with native Miracast support sometime in 2013.

Under the hood

Google's Nexus 4 has a 1.5Ghz Qualcomm Snapdragon S4 Pro quad-core processor along with 2GB of RAM. You can crunch benchmarks all you want, but here's what matters: When it comes to real-world performance, this phone is fast. Really fast.

The Nexus 4 flies through app-loading, Web browsing and multitasking without a single blip or stutter. Home screen swiping and system animations are smooth as can be. I've put this phone through its paces, and no matter what I've thrown its way, I've yet to see one performance-related fault.

For perspective, most Web pages loaded a solid five to 10 seconds faster on the Nexus 4 than on the Galaxy Nexus when I performed side-by-side tests, with both phones on Wi-Fi. The Nexus 4 also booted up about 30 seconds faster than the Galaxy Nexus.