Yeah it's a pain. A big part of it is the hassle of returning it if needed.
In our house we have 3 mattresses, all are very good.
Sleep number ile - my mattress, 7 years now. The adjustable setting is really useful to find what your comfort level is, and helps in the future with picking a non sleep number type because you know firm vs soft preference. Also has a built in memory foam top layer. I'm thinking we will probably stick with sleep number when we replace it. No manufacturing problems, materials holding up well.
The Dreamcloud mattress - on the firmer side although i think we ordered the 'medium' type. Used in our spare guest room. I will say it is several years old probably 3+, I was going to buy another one last year but read reviews that the company had negatively changed the product... leading us to buy a
Saatva latex hybrid - nice medium firmness, used by older child. Everyone really likes the mattress as well. Also no problems about 1 year in.
No complaints about any of these. I would rebuy any again (except for the question of dreamcloud changes).
Edit - I will say the sleep number was also really useful in that it did take about 2-3 months for both of us to find our preferred firmness levels. I was way off on my snap in store judgment so fwiw