Hi demaximis,
Welcome … and I’m glad you found us 
The “one size fits all” approach can certainly simplify and streamline the shopping experience but the tradeoff is that they may not be the best “match” or the best “value” compared to other mattresses where there are more options available. There is more about Casper, Leesa, and Tuft & Needle in post #3 here and there is also more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses.
I’m looking forward to finding out what you end up deciding and you certainly have many great options available to you depending on the types of materials or the types of mattresses you tend to prefer.
Phoenix