It's okay if you have two tiddlers for the fixed bunks but if you have a pair of teens then it's not okay. I'm not denying an adult could fit comfortably on the mattresses but getting in and out of the bunks, sitting to read etc are the problems. That is why we went for the layout we have in our current GT65 Turin so we have our double and the girls all have a single with no height restrictions. Yes we've lost a big bathroom but we manage quite well for weeks on end on sites with no facilities.