We have been using the Serta Perfect Sleeper Nurture Night queen size mattress for about 2 months now and love it. It is just the right level of firmness but forgiving so you gently sink into the mattress without it actually being "soft". It still maintains it's support and comfort throughout the night and is pleasantly cool. Whether sleeping on our side or back, we've not had any issues whatsoever. Since it has only been 2 months, it is hard to tell how well it will hold up, but so far, so good. Feels like a high quality, well made mattress that we should get years of use from.