The Sealy Posturepedic Spring Tight Top Firm II mattress replaced a previous Sealy Posturepedic firm mattress model for me. My first impression was that it was noticeably slimmer than the previous model (4 years old). The first few days, the mattress was really stiff so I had some initial concerns about the comfort level but after about a week of breaking it in, it was just the right level of firmness. I have a bad back and sleep issues so investing in a high quality firm mattress is really important to both my physical health and my quality of sleep. I have been sleeping on this mattress now for just over 6 weeks and have noticed a difference in both. I've had less back spasms and am able to sleep through the night more often than on my previous mattress. Although I received this mattress in exchange for my review, it is definitely something that I would invest in and recommend to friends and family.