I pretty much ignore the comments or idea of "upgrading" or "moving up" as I makes no sense at all. It's a matter of what works for each of us. What good would a DP be to a person who wants to drive a small vehicle and park in remote places? What good is a teardrop to a person like me who wants a lazy boy and all the comforts of home? As Sam says going to a TT is better for him. If I croak a better rig for my wife would be a class B from a FW.
I guess if I went from my FW to a FW with more features I would consider that an upgrade. I wouldn't necessarily even consider it an up grade to go to a newer FW because it wouldn't necessarily fit my use. I would cringe at seeing another rock ding in it or having to drill another hole in it or dragging a tree branch down the side.