Hi David, may I ask what you hope to get out of these sports, and what other guns you own, or intend to own?
To be more specific, do wish to carry, and/or keep a handgun around for self defense? Either the one you are buying for these shooting sports, or another gun that you have, or plan to buy?
Reason I ask, when I made a decision to buy a handgun, my first handgun, I had already gotten a little interested in the possibility of IDPA, and so I factored that into my decision process, at least as much to confirm the gun I wanted to buy was suitable for use in IDPA.
Reason I ask what you want to get out of these sports, some want to be super competitive, and score well, others want to become more proficient w/ their self defense weapon, and don't care as much about scoring.
For me, I still shoot my Glock 19 compact in IDPA. Would I score better w/ a 17, or special competition Glock w/ a longer/ported barrel, and lighter trigger, and heavier spring, etc., probably.
I still have the option to by a cooler competition gun, but I started w/ the gun I was gonna carry, as that was the most important thing for me.
Even if you want to have a special gun for competition, but you also want to get more proficient w/ guns you carry or keep around, then maybe it makes sense to buy a similar platform relative to your defense weapons.
Like maybe you carry a Glock 26 sub compact, or a Glock 19 compact (these are all 9mm for comparison), but maybe you buy the Glock 17 full size, or whatever the long/ported barrel competition gun is in that caliber. Or maybe you carry a .40 or .45 but get a 9MM version to run competition and practice with for reduced recoil and cheaper practice, while on the same platform as your defensive guns.
Others do the same w/ 1911's, they get a nice full size .45 which they carry on occasion, but when stealth and wardrobe dictate, they have a smaller compact 1911 style in the waistband.
So, while everyone has an opinion on which brand/model, I would first look at it from a higher level, relative to what you want to accomplish in the sport, and what skills you want to develop and carry over to your carry/defense world, relative to the platform you want to run, and then narrow it down to make/model, and see if they fit your bill.
As for my recommendation, the Glock line has a lot going for it. 33 rd magazines in 9MM that fit all sized G's in 9mm.
I also like the SW M&P in general, has a lot going for it.
I can't speak for the other sports, but I know a lot of people in IDPA klike 1911s or Glocks for the various advantages they bring to the sport. I think the availability of a stock extended mag release and extended slide stop is one thing some Glock people have utlized to their advantage w/in the IDPA rules, but don't quote me on it, it's been awhile since I read up on that, and what other guns offer the same...
Karz