That is hard to say. I have only towed "bumper pull" types of trailers. (TT, Boat, flatbeds, U-Haul Car trailers and U-Haul box trailers). I have not towed a 5th wheel, but Travis and I have discussed the diffenences quit a bit.
I like my TT, it is a 21' Coachmen Cascade TT weighing in a ~5000 lbs. I have towed this trailer with a Dodge Durango and my Excursion. Both vehicles would tow it, but the Durango was a 60-65 max speed and even with the WD hitch and sway control the trailer would still muscle the truck around. With the exact same trailer and hitch hooked to the Ex, I can set the cruise at traffic speed and "just drive", but with that being said, my truck is a SWR "F-250 Shortbed" (the Ex is built on the 3/4 ton SuperDuty Chassis) that is running a 6.0 PSD and 3.73 rears and the 5 speed TorqShift Auto and my PSD is ~325hp / 560tq so I have a bit of gearing and Horsepower advantage on your truck.
Travis (argve) has towed a 31' TT, 2 30+' 5ers and boats and flatbeds. A major difference between a TT and a 5er is the front wind load profile. A TT is not really that much taller than the truck. A 5er you have to remember, has a "room above the hitch" that you can stand up in, and that floor is just about even with the rear view mirror on the windshield of the truck, which puts a 6+' "wall" above the roof of your truck. This puts a lot or wind drag on the tow vehicle, since you are now driving a 12' tall truck instead of a 6'tall truck. He has said that a 5er does tow very nicely. "It feels like one big unit" is what he has told me when he towning down the road. There is no sway like you get from a bumper pull. But manuvering and backing is quite different. "With a 5er, take everything you know about backing and throw it out the window" was the quote. Remember when you are backing a bumper pull trailer, you are pushing the trailer with a pivot point that is "in front of" the rear bumper, so the pivot opint to turn the trailer is some distance away from the rear wheels, so you can "scoot the trailer, "over there"" when backing by using the overhang swing between the rear wheels and the ball. With a 5er, the pivot point is "directly above" the rear wheels, so in backing with a 5er there is more work in getting it backed where you want it, since you have to move the entire truck to where you want to trailer to go, instead of moving the ball...... i hope that makes sence. I love to tow and have towed alot of bunper tow types trailers, and if the trailer is long enough, I can normally back it where I want it on the 1st or 2nd try. (My little 8' flatbe utility trailer is a bit*h to back up.... it reacts to quickly and you end up chasing it alot... I hope to try a 5er at some time to compair, but with the truck you are using and the size of TT you are talking, that truck should not have much trouble towing it..... it may just not be really fast, with either type of trailer.
One thing to remember with an IDI, and this is a quote right from Trav"
With an N/A IDI I can tow anything I want at 45, and with Turbo I can tow anything I want at 55." Just remember these trucks were designed when the national speed limit was 55, and they work well at those speeds, when my truck was designed, the national speed limit was 70 and they work well at that speed.....