OK, I'll throw out a couple of thoughts:
I see lots of talk about the difficulty of setting up a 5er, will if you get a newer one, many have hydraulic auto leveling. Hookup and disconnect of the TV & 5er is quicker and easier than hooking up a Toad to a MH.
We have a 40' 5er and travel with friends with a 40' DP. Size wise we almost equal in height and length. We setup and teardown in pretty much equal time.
Yes they do have more outside storage, but I think we have a little more inside.
We sold our Honda 2000s and went with the on-board Onan 5.5 that can run everything in our unit.
As far a pit stops, we need to get out and stretch our legs anyway. And we only have one drive train and engine to maintain.
Some have given extremely optimistic fuel mileage numbers, read other threads, typical miles with a Diesel TV is 9.5 to 11.5 almost regardless of the actual weight of the RV.