I have a 2014 3.7 EB with full tow package and 3.73 rear end. We are shopping for our first TT, and based on a ton of feedback, we are electing to limit ourselves to something with a GVW under 5000#. We are admittedly conservative in our estimates, but will be on some less-travelled routes where support will be unavailable. Our mantra is safe over sorry...
IMHO, manufacturers specs and towing capacities are optimistic to promote sales. A friend fell into the numbers trap, and is still recovering from a very expensive truck failure towing "close to" his towing limit, out of country.