The frame rate in game is perfectly fine. I've encountered just a few stutters and there is a lower frame rate in cutscenes. I also found my 3DS heated up a huge amount though I have been on it for hours and it is plugged in charging too. Some textures look quite poor. The colour is greatly improved though. The controls are also much better, even without circle pad pro. Not sure why the 3D turns off when you enter first person shooting though, that was a mystery.
Definitely one of the top 10 3DS games so far imo.