Great once broken in
I have the Serta Pine Futon Full Size Maple Mattress for my pull out tri-fold couch and I find it to be okay on first use, but once broken in it becomes great. I can definitely feel the cotton in this mattress, but the 1 inch of foam is almost none existent, which makes this mattress feel even harder. Even though this mattress is very firm it has enough flex that I can fold it up in the couch without the mattress sliding off the frame. Despite its firmness I can vaguely feel the sofa bed frame through the mattress. Luckily enough it doesn't hurt because the mattress is very stiff, but this positive attribute presented a problem initially. When I laid in one position for several hours it started to feel like I was sleeping on a rock because it didn't conform to my body. I decided to remove the mattress from the sofa and walk over it for several days in hopes it would soften up. It took about a week of walking on this mattress several times a day before I noticed a change in its firmness and now it has enough give, which enables me to lay in position much longer. I would definitely recommend the Serta Pine Futon Full Size Maple Mattress because it's light but firm and will last for years.