Well, I had a Bean in my living room for the first semester of school (it's my suitemate's). She had it for exercise--but never used it. I happened to like using it as a foot rest. Sometime toward the end of last semester, her sister came over, cleaned our living room and deflated it--neither of us have re-inflated it since
So, I can't speak to it's magic powers--but it is a nice foot rest. I imagine it's just as effective as using a regular workout ball.