We went from a small class C to a TT for the reason bobndot points out. While it may have been slightly easier to set up, it was a pain to get around in and park as we were sight seeing. Also, each time we left the cg we had to detach everything. Yeah, we could have towed a car, but to us that defeated the purpose.
Also to a tt advantage is less mechanical parts (no additional engine and trans to maintain) less to register, less to insure (actually no insurance required).
My class c got 7.5 mpg all the time. I get around 12 towing the tt and 20 not towing.
Are there advantages to a MH? Absolutely! Someone mentioned not needing to leave it for breaks and in bad weather. Very true! But to us, and this is a personal decision, the benefits of a tt outweigh those of a MH. That being said, there's a lot of satisfied MH owners out there!