IDPA is a game, Its all about shaving time. Its about moving which way is the fastest. If you have a gun tuned into your load, it reduces time. time saved by less muzzle flip, less time acquiring sights for long shots. Just like the 1911 guys sometimes go as light as 12# for light loads.
If you are in the sport, and you dont think about these things, you arent very competetive.
Im headed to the nationals in Sept. where ill be shooting with guys who have done it longer. Im already good, I just need to be better.