Glocks for production class have always been the most popular. I always shot my Rugers, though, either P85 or P90. The P90 is my favorite. I use a Sparks summer special with it.
I didn't take the competition too seriously when I was doing it. I just thought of it as practice. I got up to slow expert times with the Ruger, pretty quick and REAL accurate. Reloading was a bit of a hassle with the P90, though, sometimes taking way too long. The tapered mags of the P85 were easier to hit the hole with. Heck, I even shot my Kel Tec P11 a few times for grins because that's what I usually carry and I wanted to see how well I could do with it. Not bad at all, actually, shot a little slower with it, but accuracy was good and no hostages died. The short sight radius takes time. But, I think it's good to use what you carry. I always figured that was the whole point of shooting IDPA.