We got a Casper a few years ago, they were on sale, don't remember the price but at the time it was a good deal.
Kinda odd (and super convenient) for your queen mattress to show up in what seems like an oddly small box that you can just pick up and carry through the house. Unboxing was pretty entertaining.
We're happy with it. It was a little more firm than we liked, so they gave us a free topper for it.
I wouldn't say it changed our lives but we've ben pretty happy with it.