Due to lower back pain, we replaced an old memory foam mattress with the GhostBed LUXE and love it. It was a bit pricey, but with the 101 day, no-hassle trial period it was worth a try. PROS: great support (no lower back pain), and sleeps nice and cool. It is also 13" high so you don't feel like you're sleeping on the floor. 
CONS: this mattress is not plush. My husband loves it, but at 130lbs I find it a bit firm. We purchased an overstuffed mattress pad (not topper) and it's fine. The mattress is heavy and there are also no handles on the sides. Lifting to tuck sheets is cumbersome and it took 2 of us to lift and position onto the full bedskirt.
Overall a great purchase!