The only thing though with removing the exhaust, you have to get it tuned. If you don't, I believe the truck computer will freak out and probably go into limp mode because it is sensing that the CAT and DPF and possibly the DEF (not sure where that is located though, if it is in the exhaust system or not?) are not connected. If you get a tuner from whoever mrbones got his tuner from, or go with the link I mentioned above about MotorOps (who is the Canadian DuramaxTuner equivalent), then it will tell the computer, in plain terms, that those parts are still there and to go about normal business.
The only problem I have heard though is that, I believe, if you ever take the truck in to be worked on and they hook up to the diagnostic port/ ECM, they can tell that you have tuned the truck before, even if you go back in and uninstall the tunes before you go and put your stock exhaust back on. If anyone knows different then by all means share. I too would love to tune my truck, but I don't really want to risk voiding the 8 year warranty. Kind of want to see how the truck does for a while before I tune and delete it.