We had a very good waterbed and didn't think we'd like any replacement. This mattress is perfect though. We've been traveling a lot and have slept on some very good mattresses but none beat this one. Came in a few days after ordering and fit our bedframe perfectly. All our sheets also fit perfect which is great because we have some very high thread count sheets. I would say it sleeps on the soft side of firm, which is what we were looking for. Also holds temperature nicely, not too hot, not too cool.
I really like it. I did think it was firm at first, but after a couple of days, it was really great! It had enough give and softness for comfort, but firmness for support and stability. When I bought this mattress I was in so much back pain, but I haven't felt any pain since I started sleeping on it!