"Run whatcha brung."
Or something like that.
Seriously though, pick the gun you want to use/carry for self defense and use that. DO NOT shoot for scores. Shoot for your own tactics.
NEVER leave cover without topping off your gun (tactical mag change). Even if it costs you 3-5 seconds, train like you want to fight. NEVER rush to the next corner to slice it with 2 rounds in a gun that can hold 8. NEVER present more of yourself around the corner than you need to identify and engage the target.
I could go on and on. But shoot it like you want yourself to perform if the problem were real life. I will with no hesitation perform more reloads than other if it is tactically correct.
Who cares about whether some schmoe using gamey tactics beats you. Did he retract his gun to high ready and scan left, right, and to the rear after shooting his stage? It costs you seconds during the match, but could cost his life on the streets. (EDITED to add that it doesn't cost you any time in a match, as the timer stops at your last shot. So it's a "free"
tactical habit to get into. I try to do it after engaging targets at the range. Do it every time and you won't even think about doing it, yet it will get done.)
I'm not anyone special, other than a Joe who wants to improve his skills for real life (which is what IDPA is all about). Your muscle memory and habit (training) are what you rely on in a fight. Shoot IDPA like tactically correct training, not like you're shooting for the best score.
Don't mean to get on the soapbox, but those who shoot this for time only are missing the point.
EDIT noted in text.