Depends somewhat on how big you are and what you are used to at home. For folks used to a queen or more, it will feel kind of tight, especially with the wall so close by on both sides. Bigger folks may feel a bit of a squeeze.
Some sizes of my former SOB trailer had 48" beds and there were a lot of complaints from some folks while others were very happy with them.
We are used to a queen at home and we have a 54" bed in the International. We are very comfortable, but we wouldn't want much less space. Fortunately, I have access to all of one side of the bed and some of the bottom, so making the bed isn't too bad a chore.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10