Aloha, Keiko!
The incredibly beautiful
Aulani Resort and Spa is on my bucket list. I haven't actually gotten to stay there yet, but my daughter and son-in-law spent their honeymoon there last fall, and I've been drooling over their pictures ever since.
The Murphy bed about 33 inches wide and 72 inches long, so it is just a bit smaller than a standard twin size bed. The big difference is that the mattress (which is about 5 inches high) sits in what looks like a low wooden box. Where with a regular twin size bed, if a tall person's feet hang off the bottom, they'll be resting on the wooden box part of the bed. That may not be the most comfortable.
My son-in-law is about 5'10" tall, and he says he could have slept on the bed on a night when he was super tired and not going to be rolling around much. He reports that the mattress was comfortable enough sitting on it, but he usually likes something a little bigger to sleep.
If there's anything else we can help with, come on back and let us know.
Mahalo, Keiko!