My Tundra is great for towing our Winnie which is under 6500 lbs. fully loaded. I wouldn't want to tow more than 8k lbs. based upon towing our Sunline trailer that we had before the Winnie.
I would concur. We were pulling a 7500-lb 34-footer and the truck handled it pretty well. (As someone on this site once said, "more engine than truck," and I think that's an accurate description.) Traded the big TT in for a 6500-lb 27-footer this year and it seems like we now have a great match.
IMO, the weak link in the Tundra is the smaller gas tank (20 gals.) That has been a bit more of an inconvenience for us than the lower payload. If we had 3 kids and 2 large dogs, I might feel differently. :)