ironbot:
Man, I just visited the links and the video clip there: when he leans the bot even just a degree, motors react, in my version, I have some 5 deg before reaction, I must take record a video before destructing the current one and upload here!
I think you're looking at the real problem now, but I'm still not clear whether the slow reaction is caused by the sensors, or your algorithm. I really think you need to write a sketch that just outputs the raw data from your gyro and accelerometer and find out how sensitive they are and how quickly they respond. Don't try to do any clever mapping or anything - just output the raw data as promptly and simply as you can.