No stuttering on my device (except perhaps the occasional tiny hickup), but I do remember that it ran pretty badly for a while. Perhaps it was fixed, or something else on the system.

Of course background tasks and/or low memory situations will cause the game to stutter, it's still essentially a _phone_ after all, running high quality 3D graphics. That you can even do multi-tasking while running the game is quite a feat.

Framerates for the most part match the video (although there are places where they drop to what I would perceive as around 15-20 FPS), and there is no noticeable lag from the accelerometer. You are probably confusing this with the inertia, which is a bit on the heavy side.

A little game called Enigma should give a better idea of accelerometer sensitivity, and it's hard to control because the ball reacts to the smallest tilt.