To address the question of bunk bed size... I (5'4" and chubby) found it very comfy last summer... I had a few inches of space at the end, and though I did have to remember not to sit straight up (on the bottom bunk) I never actually whacked my head. I think it's about the same size as the daybeds in the deluxes.
Another thing to keep in mind is sleeping position... my 6'3" nephew didn't fit well on the daybed when he was about 6'1", but his friend who is nearly his height sleeps more curled up and liked it just fine.