The old mattresses sag in the middle. Not good support, but it drives me crazy when it sags toward the middle between us. I have to fight it to keep to my side.

I'm not sure about the new mattress, except that it hasn't been broken in yet, and may still be too firm. It's some kind of dense foam or gel. Latex, I think.

And it's still off-gassing.

To be honest, I don't think I can blame it all on the mattress. This happened to my back... last year? and that was with our old mattress, which I liked. But I don't know what would have started the problem.