This is my first memory foam mattress, and I'm still undecided. It's not the most comfortable mattress I have ever experienced, however, for the price it is perfectly adequate. I haven't had any back pains since sleeping on it, so I guess it is doing the job and I have experienced a good deep sleep. 

The mattress quickly expanded, and I slept on it after about 30 or so hours of unfolding and it had fully expanded into the king size bed frame. 

The mattress feels fresh and unlike sprung mattress has no noises if you toss around in your sleep. And there are no spring movements etc. I would recommend for people looking for a well priced, comfortable, solid mattress.