didn't work for me, but their return policy is nice.
I would not bother purchasing this product unless you already tried it somewhere and truly liked it.  I just took a chance and tried the "Royal" model.  2" thick.  Thought it would be very soft, cushy, and comfortable.  But it's kind of firm.  I think if I were 400 lbs, it might feel soft, but I'm only about 235 lbs, and it felt very firm.  And it just made my seat height 2" higher.  Tried it for 20 days and could not get comfortable, so I submitted a request to return it.  The nice thing is that their return policy allows you to donate it to a charitable organization, and by submitting a donation receipt, you get a refund.  Product didn't work for me, but their return policy is nice.
Rating: 3 stars