Nokia now has four Lumia smartphones in a lash-us-to-the-deck re-launch that sees the company cast off the cuffs of its unfashionable Symbian operating system in favour of something new and unknown, Windows Phone 7.

The new budget model is the Lumia 610, followed by the model reviewed here, the Lumia 710, rounded off by the 800 and top-of-the-range 900. The final model has it all – a multi-core processor and a large screen, leaving the other three to fight it out at different price points below that with a mix of 3.7 inch screens and single-core processors.

We could offer a tedious comparison between the different models that explains why one is cheaper or more expensive than the other but in truth they exist because the mobile networks need them to fill consumer niches roughly 120 euros apart from one another.

When it comes to the Lumias, the spec is really a small corner of a much bigger picture in which two apparent giants of the computing and mobile world, Nokia and Microsoft, desperately attempt to rescue themselves from an abyss they appeared happy to fall into not that long ago.

Having dawdled around for a decade or more with its plodding Windows Mobile OS, two years ago Microsoft suddenly woke up and realised it needed to throw serious money at turning itself into a contender in smartphones before rivals made all the money.

And Nokia? Having dawdled around for a decade or more with its suddenly obsolete Symbian mobile OS, two years ago Nokia suddenly woke up and realised it needed to throw serious money at turning itself into a contender in smartphones before it went out of business.

On the evidence of the Lumia 710, the fusion of Nokia’s conservative but reliable hardware design and Microsoft’s unexpectedly excellent Windows Phone 7 Mango, is a qualified success.

The good bits about the Lumia 710 start with its responsiveness, allowing the user to move around the clever Windows Phone interface without any perceptible delay, coupled to a bright, clear 480x800 pixel ClearBlack TFT screen. Games run well, apps perform as they should and even browsing happens at a decent speed thanks to built-in acceleration. 

Where most 5 megapixel phone cameras are mediocre, the Lumia’s does its job well, snapping rapidly and to a very respectable quality not that far behind a basic compact digital camera. LED flash is included as is acceptable 720p HD video. Not outstanding but perfectly usable then.

The less good bits are the average battery life and fixed 8GB pool of storage which complements 512Mb of RAM. There is no SD card slot to add more storage; once it’s used up it’s used up. We also noticed that the mini-USB port for desktop charging appeared to use a wider pin-out than we’ve encountered before and failed to fit any of our third-party charging docks or cables.

More generally, the 710 still feels like a Symbian smartphone that could have appeared at almost any point in the last two years. This isn’t a negative exactly but with its conventional lines, top-mounted unlock key doubling with the power button and poky rear speakers the design lacks drama for a device costing at least £250.

Included software covers all the obvious social networking bases plus the ability to connect to one or more of a number of web and pop email services; Bing search and IE9 with accelerated graphics and HTML5 support are included as is Microsoft Office, SkyDrive and synching with desktop PC using Microsoft’s uncomplicated Zune.

One thing you can’t do is feed Google’s calendar data into the supplied calendar app using push; getting at that means a live browser session.

The Lumia 710’s best feature is really Windows Phone itself, which can be learned by novices in half an hour of poking around. All major tasks are simple to work out, from installing and deleting apps. The only weaknesses we could see was the tendency of the battery icon to disappear (requiring it to be pulled down manually) and a general sense that the user could not get 'under the hood'. This is not an OS that wants to be fiddled with or tweaked out of the box.

The biggest weakness of Windows Phone 7 for now is the number and sometimes the quality of marketplace apps. Most well-known apps are available in Windows Phone versions, but a few aren’t or are but don’t work that well. It’s clear developers are putting their money where the market (Android and the iPhone) is and Windows is just some way behind. The good apps are also more likely to be charged for.

Reviewed on Vodafone, which offers the 710 free on monthly tariffs starting at £20.50.

OUR VERDICT

Conclusion: For all that the 710 is a Nokia, the selling proposition rests pretty squarely on the nature of Windows Phone itself. With low expectations of the OS I was prepared to be disappointed. And yet overcoming all my prejudices, Windows Phone 7 looks as if it could be the best thing the company has done in the consumer space in two decades, perhaps ever. It’s easier to get to grips with for a novice than Android and in some respects makes the iPhone look about three years behind the interface zeitgeist. For all the iPhone homescreen’s sleekness (or in Android’s case, lack of it) the future of the smartphone might have a place for Microsoft's tiles after all.