This Beauty Rest Silver is very firm.  You’d think it wouldn’t be comfortable being as firm as it is, but it actually is!  My back hasn’t hurt anywhere as near as much as it used to.  I actually fall asleep quickly and wake up less frequently as I used to.  If you have back issues, this is the mattress to get! It’s also very thick and higher off the ground, so it’s easier to get out of.  I have this on my adjustable bed and it works perfectly.