For the price, I recommend it.
I bought the softest one in a California King size; getting anything stiffer is not logical because by design the bed is firm.
I had no trouble installing it, I gave it about 30 hours to fully enlarge, no problems with the size fitting the frame. One nice thing about it, when you exit the bed the edge gives you a slight push so it's easier to get up. Remember, the foam is flammable, so keep fire safety rules at all times. Works for me and my wife.