Just ordered my Casper after months (and months) of deliberation. I'm not expecting a miracle bed or anything, but it was nice to buy a mattress without having to deal with a mattress store. We shall see how the bed itself is once that arrives. If anyone else is thinking of buying one and wants to save $50 in the process, let me know. I can PM you a referral code.
Hope it works out for you! I've been using my Casper for a couple of weeks, now. I'm still not totally used to it -- honestly, it still feels a little weird compared to any other mattress I've owned (most recently memory foam on a spring mattress) -- and yet I'm sleeping better than I ever have.
It feels really firm, overall. Whenever I lie down, I think it's going to be too firm to sleep . And yet it always gives just enough where the pressure is highest, so that there's no uncomfortable position. I fall asleep fast, and I don't shift much during the night. I woke up a little sore after the first night, but not since. One of the things I like about it is that it doesn't heat up too much, unlike memory foam.
I'm really glad I got it, so far. Only two caveats. First, it stinks. At least mine did. It's still got a strong smell to it. I'm washing my sheets every two or three nights and letting the bed breathe during the day, and only now (after two weeks) has it really begun to fade. Second, if you share your bed with someone else, and if you're used to memory foam, the Casper may make your (or their) movements feel more conspicuous. It's not noisy, just a little bouncier.