We've had 4 different fulltime units.
We started with a 40' enclosed bath w/triple axle to a 36' split bath. Then upgraded to a 38' enclosed bath. We just upgraded to another 38' because we needed a slightly larger closet, more basement space and most of all the 48" shower in the enclosed bath. But now we have a slightly smaller living space, but have more upper cabinets and counter space in the kitchen than the last unit.
Floor plan is everything. We've been in slightly larger units and they weren't as well laid out or feel comfortable. We've been in smaller units that one portion is great and cramped in the other.