We went for floor plan rather than chassis and are extremely happy we did, especially since it is only 34' (we fulltime).
First requirement - everything had to be usable with the slides in - tv, bathroom, kitchen, bed. This alone knocked out a lot of contenders.
Second requirement - a tv in a viewable location for the living area. Not up front, not in a pop up behind the dining table, not in a neck-craning location. This knocked out quite a few more.
Third requirement - a seating area where two people could lounge comfortably. This knocked out even more.
Fourth requirement - a gravity fill water tank option. Not floor plan related but, since we boondock and dry camp, a requirement learned from not having one.
We found the perfect floor plan for us in a gas Bounder so, even though we wanted diesel, we bought it. We absolutely love our floor plan and the only thing that would make us trade is our exact floor plan in a diesel. With no carpet. I really hate the carpet. And I want a large window in the back. Chances are we will never trade ours in...