We have the king size love how supportive this mattress is for our backs, very comfy and were both sleeping better now. 
We allowed ours to fully expand for 2 days and then we put it on our bed. Now we did have adjust to the mattress being lower than what we’re used to. Our old mattress was a pillow top and 14” deep, this mattress is 10” deep. But, again, so far so good. Love the fact there a 100 night trial on this.