I've used it before. Performs quite well but I didn't like to have to keep adjusting its position on the flash. When in use, you have to position it such that only the bottom third of the softbox covers your flash. The rest must not cover the flash.
When I need to keep my flash, I will either have to take the whole thing off or push it down the flash completely. I found that it's not very easy to put it back on the flash if I take it of completely. Often I found myself fumbling with it.
So, I got myself a Stophen Omnibounce instead. Don't have a complaint about it. I can take it off or put it on in a split second. And I don't have to do anything about it when I keep my flash.
One disadvantage of the Stophen Omnibounce is that you can't use it on a different flash - you need to buy a new one. On the other hand you can use the same unit of Orionbounce on practically any flash.