From an ergonomic perspective the 360 controller is pretty bad (but better than the original XBox controller, which was horrendous). This comes from a physical therapist (I treated many hand problems) who actually works with ergo therapists, we discussed this topic during a few coffee breaks.
It's basically too big for small hands and the button/stick configuration is too asymmetric (ignoring also left and right handed people) and doesn't take into account the MLPP/range of motion of the thumb.







