It’s been a week, and we both like it. Holly says she doesn’t really sit up with “good” posture, and I have to agree. I’m a chronic sloucher and the ball doesn’t fix this except for when I consciously tell myself to sit up straight. But it’s comfortable sitting, and it’s more fun than a regular chair, if that makes sense. But this is not for 40+ hrs per week professional desk work. It’s good for about an hour or so, and then you wish you could sit back and relax.