I just looked at the FR website to get an idea of what you are talking about. I believe the Aviator line was intended to compete with Airstream, while the Pilot line looks to be much like LaCrose, Coachmen, Surveyor etc is general appearance, however with nicer finish and amenities.
As to your question about TT vs. 5er, we have a TT mostly because our tow vehicle at the time was not a pick-up but a 3/4 ton SUV. Now I have roughly the same truck you do. I have thought about a 5er, and here are the things that stand out to me.
-more overall room, broken up with more clearly defined "areas".
-more basement storage
-theoretically easier to tow, manuever etc.
-lower profile makes it easier to store, less likely to hit gas stations etc.
-no inside steps, less broken up floorplan
-usually lighter overall, and less tongue weight means you can carry more stuff in truck.
So while we could step up to a 5er now, I don't really want to. The exception would be if we went to toy hauler, but that really puts me into a bigger truck, etc.
2013 Coachmen Freedom Express 320BHDS pulled by a 2005 F250 King Ranch CC
A rainy day camping is better than a sunny day at work.