We've had E-450 based Sunseekers and a Transit based TS2390. After driving a Transit it is hard to go back to a E-Series. The independent front suspension, and the size difference, make the Transit a pleasure to drive. While it is not a sports car the improvement over the E-Series is very noticeable.
The day after we bought our TS2390 I drove it 500 miles and was ready to keep going...
I've never driven that far in a day in a E-Series, normally I went around 350-400 miles, and feel beat to death...
Our TS2390 averaged around 14MPG with a high of 17MPG and a low of 11 MPG. the E-450 on the same route averaged 7.5MPG.
As far as towing FR does not install a hitch. Coachmen installs a Class One 1,000 pound rated hitch. I looked at adding a Class 3 hitch to our TS2390 and due to the frame extensions it is not a good idea...if it could be done at all.