Sarge,
I have a Forest River Sierra F30 (30') toy hauler. Last time I weighed with the Jeep in it, I had 12,000 lbs on the axles (upgraded to 16" wheels and E load range tires), and 21,500 lbs GCW. My '98 2500 towed it for 3-1/2 years with no problems, except for two trips the first year where the auto transmission scared me with some slipping; never a problem after that, though.
Haven't pulled it with the new truck yet--still need to find the right 5th-wheel hitch to install.
Mark