Hi goinggold!
I have a 2013 298RE Outback and absolutely love it. We've made several trips to Florida and back again now, and travel as far as money will allow. Granted I am towing with a 3500 diesel duly (Chevy), but with my set-up, it tows like it's not even there. The only time I notice the trailer is behind is when making a turn.
I have no clue how a gas engine truck would tow this trailer, nor a single rear wheel either. I do know, my duly is so stable it's very easy to forget 35 and 1/2 feet of trailer is dragging behind.
My truck also has the integrated brake controller and works so smooth with the truck, the two brake as one unit, even on sudden stops. No jerking, yanking, or anything.
I use an Equal-i-zer 4-point Weight Distribution hitch system which does level the truck out. Even that 3500 duly will squat about 2 inches without the WD bars. With the bars, it's hardly noticeable.
There is a 2 mile-per-gallon difference between towing and not towing this trailer.
I would think a 2500-HD GMC would tow this trailer OK.
See my "profile" on the left.