Quoted:
IDPA can provide a valuable training experience, if you approach the stages as training stages, rather than attempting to game the stages for the purposes of winning.
That may be true. But are you actually "applying sound tactics" when you shoot IDPA? Supposedly, the IDPA rules were written so as to penalize you for not using sound tactics, so why is that an issue? (no - I'm not criticizing cmeyre001. I'm just using his comment as an example.)
So are you actually using sound tactics, or are you just shooting slower than the people who do well at these matches? What kind of feedback do you get? Is there a "trainer" there to critique your run after you're done? Or are you just practicing poor tactics, thinking you're doing good?
If you want training - take a class.
Shooting competition is a lot of fun. You will get better with your gun by doing so. But a game is a game. It's still not "training".
But then I ask the question again - what do you want to get out of "training"?