Been away for a couple weeks since I swapped trucks for the 08 gasser. The good - my wife will drive it (save some wear and tear on the Corvette), all the Laramie gadgets I didn't have on the SLT, it will fit in the garage (once the Chevelle gets picked up by the new owner) and mpg is about the same.
The bad - the dually looked cool (never used it for what it was built for), the turbo whistle is no more, MDS just plain sucks (don't think it really helps mpg - my 04 got the same). Superchips and Diablosport are supposed to have a tuner out that will be able to turn the MDS off. Performance reduction - the diesel felt stronger (but I get my real performance fix on my bikes - will be getting an 08 Kawasaki ZX-14 the end of the week - high 9's 140+mph quarter mile bone stock).

It has ended up being a good move for me because I reallly had very little depreciation over the 2 model years. I would not have traded if there was going to be a big cost to me.

I do like the look of the 09's with the tighter body and tucked bumpers.