Tow haul mode even when I am not towing - keeps the RPMs up in town and helps with "engine braking". With the truck and trailer we are a little over 20,000 lbs.
Our truck has a little over 23,000 miles on it - only problem I had so far was a dead passenger side battery - replaced by the dealer.
I use the exhaust brake if I will be going down a decent grade. It works good - there is a down hill grade on route 81 in PA that I had to use the brakes on my 2005 D/A. With the 2011 I set the cruise at 65 mph and about 68 to 69 mph the exhaust brake kicks in and I do not have to use the brakes.
The real test of the exhaust brake will be our trip out to Yellowstone and Glacier this summer.
Towing - remember to change the rear diff fluid - changed mine after the first 600 miles of towing - gray and milky. Changed again when I put on a PML diff cover and it was clear and clean.
I changed the shocks at 22,000 miles - the OEM shocks were shot. Rides better now when towing.
Mods on my 2011:
Bed Rug bed liner, Luverne SS running boards, Air Lift LoadLifter 5000 air bags, Reese Custom Base and Rail Kit, Handy fifth wheel tail gate, rear wheel liners, rear seat storage tray, front lower bumper billet grill, PML rear diff. cover, Bilstein 5100 shocks, Edge Insight CTS.
2017 Keystone Avalanche 320RS
TV - 2011 Chevy Silverado 3500HD LTZ CCLB Duramax SRW 4X4