Windy,
I think the '03 mattress is firmer than the older ones and the new top shell construction is lower. TM probably lowered the roof as much as possible to allow garage storage with the rooftop low profile AC installed.
I'm going to purchase a Travasak system (
www.Travasak.com ) for the bed. That way I can store a made up bed on the front couch while the TM is folded.
MJL