Randy, I have a Z71 1-ton with the Duramax/Allison 6spd. Like yourself I went from a 5.3L Z71(2001) to this one which is a 2010 model yr(365hp/660lb ft). I'll be using it this year to pull some equip't I've got on order(about 10,000lbs) but so far I've just been using it as my driver. Compared to the old truck, obviously I've got crap loads more power, on top of which I'm getting much better mileage(highway, city not much diff). The 2011's will give you even more power and better economy over the '10s, btw. Having driven the truck for 7-8 mos, I prefer it over my gasser...actually seems quieter on the highway due to the lower rev's combined with the 6 spds and actually goes pretty quick when you want it to. Can't give you any thoughts on towing just yet, but I'm thinking this truck won't break a sweat with a few tons behind it. I've had no more than 1400-1500 lbs of stone in the back so far, not even noticeable except it settles the chassis down and rides smoother with the added weight. The 11's require urea(same w. Ford), but the 10's and earlier don't require it so take that into consideration reg fuel mileage....11s get better mileage than 10s but you also pay for the urea which evens it out somewhat.
