I read a lot of reviews about this mattress; some good, some not so good. I took a chance and bought it to replace our waterbed mattress. The cali-king is the same size as a king waterbed, so it fits right in the frame. The mattress rises about two inches above the sides of the frame, which is perfect, and all our sheets fit it. It took a couple of days for the mattress to "inflate" to its normal size and firmness, but it is like a dream now! The first two days, it was too hard, but since it has fully expanded, we are really loving it. I don't wake up every time my handsome husband rolls over or gets up. No moving, shaking or waves anymore. Nice, firm mattress that fits perfectly and feels great. And, the prices was a dream.