Personally, I'd be leery of anything that I use daily but am unable to try out before it gets set up in my home.
The last time we mattress-shopped, we went to over a dozen stores before we found the right mattress- the moment I lay down on it, my spine cracked and aligned and the spouse had a similar experience.

I know Purple and other internet companies have convenience on their side, but with personal, subjective things like mattresses, you kind of have to test them and kick the tires before laying out that kind of money.