Generally I prefer a ROM that’s as close to vanilla Android as I can get, so plain old Codename Android was an obvious choice. It's the first ROM that I tested.
Thankfully this open source ROM has everything necessary to replace the stock Android OS in daily use. Here’s how Codename Android performed when I put it through its paces.
This can be an issue for a lot of ROMs, with force close errors being as annoying as Windows' infamous Blue Screen of Death. Thankfully, Codename Android is as reliable as ROMs come. As a test, I installed the Angry Birds and Google Currents apps and made extensive use of them, as well as noting whether any apps crashed.
I found Codename Android to be extremely reliable: Apps didn’t crash, and the ROM itself remained rock solid and stable. My phone did boot up a tad slower running Codename Android than it did running stock Ice Cream Sandwich, but that isn't really a concern. The camera in particular was more snappy than stock when opening from the lock screen.
I don't have a lot to say here. Codename Android felt like one of the fastest ROMs I played with during my testing. It's designed to be a speedy ROM, and the developers delivered on that promise. Even after I turned on all the extra screens (seven in total) and customised nearly every facet of the ROM, using my phone felt gloriously fast.
Installing Codename Android is as easy as downloading the appropriate ROM for your device, rooting/unlocking your device and installing the .zip file from recovery mode. Installing the Franco kernel adds some annoyance to that process, but it’s just another file to install from recovery, hardly a dealbreaker. In my tests, the initial boot after install took a couple extra minutes and I always sweat that time, fearing I did something wrong, but it installed without any hitches.
Codename Android feels like stock Android, with some additional cool things stuffed into it. You'll find none of the carrier bloat, of course, and you won’t see anything like the cumbersome HTC Sense overlay here. It’s a pure, unadulterated Google experience, and it’s awesome.
The developer claims that Codename Android improves your device's battery life, and with the addition of the Franco kernel I did see an impressive gain over stock Android. I easily could get 12-plus hours of moderate usage from my Galaxy Nexus, which is a good 1 to 2 hours more than I could eke out on stock Android. I didn’t expect to see that much of a difference, honestly.
Codename Android is one of the best ROMs I’ve used for ICS. If you want something that looks and feels like ICS but has a ton of additional swagger, get Codename Android.