I wondered if it would be worth the money (and decided it was)
I've had back problems for years. I used to use a ball chair but lately that hasn't been too comfortable either. Decided to try this product and so far, I have been very happy with it.  It is comfortable to sit on all day (I work at a desk all day). It's also portable, so I have taken it with me when I need to work in another location. It's expensive but I do think it works well.
Rating: 5 stars