I assume you're talking about me 956 - I assure you that I am absolutely NOT the TDR's best. Believe me when I say I looked into this VERY closely before I made the decisions I did. Everyone has to look at their personal situation, how the truck is equipped and loaded, what you put in the back of the truck, what trailer and how it's weight is distributed, etc. Let's look at MY rig with actual weights straight from the scales (this was with my wife, myself, my 6 month old daughter and my husky in the truck, my motorcycle and a bunch of wood and tools in the bed and the trailer behind me - this was right after I bought the trailer and didn't have as much stuff in it):
----------------------------Actual--------Rated
GCVWR-------------------15860-------18000
GVWR---------------------9260----------8800
front truck axle---------4480-----------4850
rear truck axle----------4780-----------6084
trailer axles--------------6600----------8500
As I said above I am over the GVWR of my truck by 460 lbs, however if you look at the components on a 5sp 2500 and a 3500 you will find that everything is the same with the exception of two extra tires on it (I researched this very carefully as well). BTW, a weight distributing hitch wouldn't affect the amount of weight carried on the two axles put together at all - it would simply shift some of the weight forward. Now, let's look at my axle weights. My front axle had 4480 lbs on it and is rated at 4850 lbs so that means I was at 92. 4% of it's capacity. My rear axle had 4780 lbs on it and it's rated at 6084 lbs (which btw is exactly what the two stock tires added up to, they were rated at 3042 lbs each, my current tires are rated at 3305 lbs each) so that means I was at 78. 6% of it's capacity. Now, if I put a weight distributing hitch on the truck I would have transferred some of the weight that was on the rear axle to the front. Therefore I would have reduced the 7. 6% margin that I had left on the front axle and increased the 21. 4% margin that I had left on the rear axle. Personally, I feel safer having a larger margin than a smaller one.
Everything in my hitch setup is rated for 10,000 lbs trailer weight and 1,000 lbs tongue weight with a straight hitch which is well over what I'm running. The hitch is rated to 12,000/1,200 if I had a weight distributing hitch plugged into it. I can tell you that I feel absolutely no rattling on my hitch setup. Remember also that a gooseneck trailer uses a ball and socket joint as well with no equilizing bars to "take up the slack", etc. Draw-tite rates my hitch setup to 10,000/1,000 without weight distributing bars and I highly doubt they'd sell it that way if it couldn't handle it.
I never said to tow above the hitch's rating, I told him if he didn't want to buy weight distributing bars that he would need to buy a beefier hitch setup as I have and keep in mind he's towing a lighter trailer with less tongue weight than I am. In my case I feel that I would be possibly reducing the safety of my tow rig by putting weight distributing bars on it because I would be putting even more weight on my front axle that is already pretty close to it's max whereas I still have a good bit of breathing room on my rear axle. Everyone has to look at their setup and how it weighs out, take it to a local truck scale and get actual weights instead of going by what the labels say, and make their decisions from there.
I realize that I am slightly over the GVWR of my truck - but am FAR less over than MANY MANY of the rigs on the road today and I have taken steps to help with that (exhaust brake, better shocks and tires, etc). I am however WELL within the manufacturers limit of my hitch setup as well as all the axle weights, etc. I feel VERY safe rolling down the road in my rig and I can assure you that there are many rigs out there on the road with weight distributing bars on them that are far more unsafe and overloaded than I am. If I take my motorcycle out of the back of the truck I am 100% within ALL of the limits of the truck and have an even larger safety margin on my rear axle than I do with it in there.