Been sleeping on this mattress for about 1 month now. Bought a new one because our old one was a 5 year old memory foam mattress and was causing back pain and stiffness. Decided to spend more money on a good bed and new technology with the hybrid memory foam and springs. 

Back pain was nearly gone within 1 week. However, 1 month later of sleeping on this bed I still have some minor low back aches which feel similar to feeling sore after a workout. Casper says to give the bed at least 1 month for your body to adjust and it's been about 1 month. Not sure if I will keep the bed before the 100 days, but will give it a few more weeks before considering whether or not to return it. [This review was collected as part of a promotion.]