I don't have any experience with the air intakes for these trucks, but on pretty much anything GM a handheld programmer is a waste of cash. Some trucks get better with them, some get worse. Go for a custom ECM tune for good results (and normally for less money) Usually a custom tune from a good shop will net better drivability and possilbly an extra mpg or two. I personally had mine tuned locally and saw 1.5mpg better and it drives almost like a different truck.