Very, very comfortable mattress for firm preferences, which we have.  4 stars instead of 5 because the edge is not as firm as advertised, and due to its 148 lbs and rolled up bulk it was a real chore to get it in place to unfold on the slat foundation and bedskirt, and once unfolded to move it in the right spot on the bed.  This California king size mattress is actually a bit too long for our new California king bed frame with footboard, and it is wedged in so tight between the headboard and footboard that I can barely make the bed to tuck in sheets and blanket there.