I don't have the HD trailering package; however, we have the HD oil cooler and external tranny cooler. The only thing we lack is integrated brake controller (big deal), 3.42's (we have 3.08's - such a tall first gear on the 6L80 - is this that big of a deal?), and 2-speed transfer case. It's downrated to 6,000 from 8,000. That seems a bit extreme, so I think I could get away with 6500 as equipped.
You all are speaking to my heart with the talk of product quality. I am a Director of Quality in a manufacturing company it drives me crazy reading about the service necessary even in the top brands.