I too like them. Careful though, I had been using an exercise ball for a chair for the better part of a year, just a couple weeks ago it popped while I was sitting on it.
A couple other caveats: 1)it can bit quite tiring on your back (especially at first) to sit on one for 8-10 hours. 2) since you're sitting on rubber, if it's the least bit warm, things tend to get a bit sweaty down there... :)
A couple other caveats: 1)it can bit quite tiring on your back (especially at first) to sit on one for 8-10 hours. 2) since you're sitting on rubber, if it's the least bit warm, things tend to get a bit sweaty down there... :)