OK...I towed my old Sunline TT, around 8500 lbs. loaded with my Toyota. It could pull it ok, but I wouldn't want to go over the Rockies with it or use it for a lot of towing, even though my truck is rated for 10,000 lbs. I just had the new Minnnie 2201DS weighed with gear, but without clothes or food, and it weighed 6,180 lbs. The truck is much happier towing it and we just made the trek from North Ridgeville, OH to Mears, MI (about halfway up the west coast of the lower peninsula. Personally, I wouldn't want to haul more than 7,500 lbs. or so with the Toyota. 10K or more...yeah...the truck will pull it, but it's not going to be very good for the driver or for the truck!!
And, I agree with those that believe a lot of folks are towing too much weight for the tow vehicle they have and are "flirting with the deveil".