Does anyone here have a foam mattress?? Like a Casper? Do you like it???

We want to get a new bed and are considering one of these as we've had bad luck with a few spring beds we've had over the years.

Casper seems to have good online reviews and we tried one out at a West Elm. But I need more info! It comes in a box, and you get a good amount of time to try it and can return it.

So do you have foam? Do you use a box spring with it? Or just platform? Like it? Hate it?