This is a beautiful daybed. Best with a twin XL mattress on the top and a standard twin on the trundle. There is a gap between the top of the daybed and the trundle, but I do not mind it. I have added three European pillows (26x26) on the back, then assorted 18 x 18 and 20 x 20 pillows to fill in. Perfect for our office space. If your twin XL mattress is tall (more than 10 inches) you will not be able to put your feet on the floor while sitting on the daybed. We mostly use it as a chaise lounge.