I’ve had two Leesas. One with my ex and now at my new place (a year old). Both were extremely comfortable and fit my sleep needs. The first was a risk, the second was an obvious choice.
I think this might be one of the big 'brand advantages' of the mattress in a box companies; because most people feel uneasy about the return process, and because of that, if they like the mattress, they are more likely to buy more of the same than to roll the dice again.