IPSC or IDPA, What do you shoot? Pros and Cons?

While I've done a few IDPA matches I'm a dyed in the wool IPSC shooter. I know IPSC doesn't require tactics but I want to shoot more than 40 rds per match. Heck, I've shot some 40 rd stages! Would it hurt the training value of the match to shoot more even though a high round count isn't likely in the real world? I do see the IDPA rational but it really does seem to me that as long as a timer is running it's a game. Tactics take time and usually the most tactically sound solution takes the longest. I'm not knocking IDPA at all, just interested in everyone's opinion.