When we got it home, we put it on the bed, and in spite of an approximate 800% improvement in general comfort, it still felt like the bed dipped across the middle. When living with the sleeper sofas of my youth, the remedy for this was a half sheet of plywood. It worked, for a while, although it was a beast to deal with: It gave you splinters, the rough edges tugged at the sheets and upholstery, and it was a pain to store in the daytime. The true flaw was that it, too, would eventually start to bow in the middle. Then you’d either have a stiffer but still-saggy mattress, or you could flip it, bowed side up, and try sleeping on a hill to flatten the plywood back out. We talked about plywood, my wife and I, but soon resigned to look for something better. Using the same “every night” types of filters in the user reviews, we landed on the Meliusly Sleeper Sofa Support Board.