Really love this bed and works perfectly with a wider mattress. The XL twin mattress extends a bit over, but it's workable. There are several reviews that mention not lining up when assembling and this was also the case for me.  I had a couple of spots that didn't line up and it was a hassle, but all in all I'm very, very happy with this purchase. I got the grey color which is really more taupe/brown but I was expecting that since others mentioned the color.