Some features are not performing well, as noted by Ubergizmo:
The thing is, the Kindle Fire 2 is not the fastest tablet on the block, so that kind of defeats the purpose, but at least it opens up options to the masses. Be warned though, CyanogenMod 10.1 for the Kindle Fire 2 will not support hardware video acceleration, meaning you cannot stream HD video from YouTube and Netflix, and you will also experience a higher battery drain during sleep while your headset microphones remain gimped.Also remember, by using custom ROM such as CynanogenMod, you are voiding your warranty. There is always one possibility of "bricking" your tablet. So, upgrade at your own risk.