StevenJ,
I own a 18' Pace v-nose enclosed snowmachine trailer (front and rear ramps, side entry door). Because it's made to haul machines side-by-side, the deck inside the trailer is flat with the tires directly under the deck of the trailer (no fender wells) This trailer sits higher than the standard enclosed trailer.
I have towed this trailer from Alaska to Arkansas and back again, to include hunting trips to Colorado a couple of times (weighed any where from 5,000 to 8,000 pounds loaded). I never once had problems with the trailer wandering in high winds (don't even use stabilizer bars). Of course, fuel mileage varied with speed and head wind.
Also, I have a 29' Holiday Rambler Alumascape TT. It would be an unfair comparison because, when loaded, it weighs nearly 2K pounds more. However, I do use a Reese dual cam stabilizer system with the Alumascape... no wandering issues there either.
Because weighing less, given the same conditions, when towing the v-nose I net about 1. 5mpg better. Hope this helps.
Dwayne