And what should I say? I was not disappointed. It is really pleasant to sit longer on the ball, he seems also shocks to filter so you do not constantly up and down "jumps". You can tell immediately how the attitude at work improves. He also appears from relatively thick and good (it does not stink total for plasticizers) to be material.
One more small note: You should really as stated in the manual inflate the ball with a pump or a blower. I've been blowing him at the start and was surprised at the small size. Almost wanted to send him back already. Now it is but - through the bellows which I had left - perfect :-)