I'm pulling an Outback 227RL, around 8K lbs loaded with a 2011 Tundra, 5.7L, tow package, and 4:30 rear end. It pulls all day long at 2000 RPM with 6th gear locked out, no problems. Like others, the gas mileage is the only drawback at 10-11 MPG towing, but the truck is also a daily drive so it meets my needs fine. For a 1/2 ton truck, I wouldn't have anything but a Tundra.
2013 F250 XLT
I now have a Keystone Outback, but I try to help when I can.
Bitter Gun Owner