AOKP stands for Android Open Kang Project – an oh-so-clever play on Android Open Source Project, Google's name for its open-source releases of Android. AOKP's a stable ROM that aims to be as simple as possible – all the tweaks are hidden in a 'ROM Control' menu, while the rest of the operating system stays pretty faithful to stock Android.
That said, when you do delve down into the depths of the system, it's got just as many options as CyanogenMod – and, in some cases, features not offered. The most centralised approach is certainly simpler, and can help you get your head around the wealth of new options available.
However, it's not quite as stable as CyanogenMod – perfectly usable, but froze a few times when switching between apps on our Nexus 4. There's also a good range of supported devices, especially older HTC, Motorola and Samsung models. ROMs for AOKP can be found here.
The PAC-man ROM is for those who want all of the cake – it's an amalgamation of Paranoid Android, AOKP and CyanogenMod (PAC, geddit?). Obviously, then, it's feature-packed to the max, with Paranoid Android's scaling modes, CM's interface quirks and even AOKP's centralized menu settings.
The trade-off, however, is that the newer builds are a little unstable. Although the ROM usually ran silky-smooth on an HTC One, certain gestures would cause it to jutter, or force it into a reboot – not quite ideal. That said, the list of supported devices is at least extensive.
6. Liquid Smooth
If you're the kind of person who gets excited by megahertz and has a whole box of spare computer bits tucked away 'just in case', Liquid Smooth is the perfect ROM. The emphasis is purely on performance and speed – the UI has been pretty much entirely left alone, as naked Android.
Under the hood, though, it's a different matter. You get a built-in menu that allows you to mess with undervolting and overclocking to your heart's content. Even without messing with the CPU settings, performance is markedly better than stock Android. The effect on battery life varied across the devices we tested, but performance could generally be improved by fiddling with the CPU settings, something's that's easy enough to do thanks to the built-in tools.
Sadly, the list of supported devices is woeful – a smattering of Samsung and Nexus handsets, but few of the older devices that could really use the performance boost Liquid Smooth offers. The full list, and ROMs, can be found here.