If you compare apples to apples...ie, you can't compare a small bare bones 5er to a top of the line MH with all the bells & whistles....
You can get a generator and auto leveling on either. You have to hook something up to tow either way (very few travel in MH without a toad).
Backing...yes it takes some practice but I'm sure the first time you backed the MH into a spot, you probably took a few tires and were slow and careful. Once you get the hang of it 5ers back easy.
Filling up: Take the truck in the night before you tow and you don't have to take the 5er into the station at all. But even if you do, it's not greatly different from a MH. In fact if you have a toad, the 5er has the advantage that at least you have the option to back out from a pump.
Given you need a 3/4 or 1 ton truck regardless, price falls heavily in favor of a 5er. At $50k, you can buy a very nice 5er (maybe not ultimate top of the line but definitely good size with nice features and mid range quality. If you are looking at a new MH, that's basically bottom of the barrel small class C range.
