It would be helpful if you posted details on the truck.
I also think you would be better off going to a forum that is dedicated to your brand of truck and get some opinions over there. You are more likely to get some balanced opinions of the advantages and disadvantages of deleting. This thread isn't bad yet, but it usually turns so with people vehemently against deletes that have very little real experience with it.
I have chosen not to delete because I value my warranty and Colorado does emissions testing. That said, the draw of more power and better MPG is strong.
