Before our 24.1 we had an F-350 and a 5er. The Axis rides so much smoother than the F-350. Of course this makes sense: The truck (and your Tundra, and to a lesser extent the Toureg) are built to haul a bunch of extra weight so the suspensions are sprung as such.
Now the E-350 and E-450 are also built to haul a bunch of extra weight, but that extra weight is already on there in the form of a motorhome (on our 24.1 we only have about 1,000 lbs to spare over GVWR). Thus the ride is much better as the "stiff" springs are bearing the weight they were designed to do (not a lot less).
I also have to agree that you're better off finding an E-450 chassis based Axis (or Vegas).
Another benefit of getting an Axis or Vegas: You can go download Ed's crowd sourced owner's manual and know everything (including things you didn't want to know!) about it:
http://www.thorforums.com/forums/f10...nual-4961.html
What part of Michigan are you in?