I don't thing the upgrade will mess up a good thing, but there's plenty of discussion on that topic already. My p320 compact might possibly be the best all around shooting gun I own. Recoil impulse, ergonomics, accuracy, sight acquisition, and trigger are all things that I find hard to beat on the p320. I'm still a Walther ppq fanboy, but I shoot the p320 just as good and it tames the recoil a little better as well. You feel the difference in 9mm a little bit, but in 40 and 45 it's almost night and day. I did some polishing on my p320 and the double clicking of the trigger that was sometimes present is completely gone. At 10 yards it's almost nothing for me to put 7 or 8 out of 10 shots through the same hole. I've done it a lot and it's almost expected now. The only other guns I can consistently do that with are my ppq 5" and Cz 75B. Still debating if I'm sending mine back to sig for the upgrade or not.