When printing the CPU usage within the app it does seem to be lower in the compiled app compared to the Chrome mobile browser, about 50% lower. Although my fps is good at the moment, it seems to jerk/lag slightly at irregular intervals.
I also noticed a delay when playing audio (already preloaded), which also happens in Chrome mobile browser and CocoonJS. It's about 0.3 seconds long on Samsung Galaxy S3, which is noticable and make timing-based audio difficult.
As I'm experimenting with a music game, my biggest issue is that Audio.PlaybackTime in C2 does not take this delay into account, so I have to manually add 0.3 secs to Audio.PlaybackTime to get the actual playback time of the song. I'm mainly worried that this delay varies across devices, which might mess up the timing. Still, this is an improvement from CocoonJS where Audio.PlaybackTime did not work at all.