Yup they will use the room. My Male "hence the name" Sully, lays all the way across the tank stretched out.. I think he likes it and it feels good or he wouldnt do it.. Then he climbs around, goes through his 12" water bowl and sometime sits in it for 2-3 min... When he is done, he goes into one of the hides.. He lives good and not cramped up and he isnt stressed. So I'd play with that enclosure and have fun working on it for him.