Thanks, Gabe. This thread encouraged me to give the 19 a try today (also, a worn-out trigger return spring on the 34 and being too lazy to replace it ).
I usually rack up a few match wins in a year at this match, and am disappointed if I'm not in the top 3, so I wouldn't say the 19 allowed me to do something I can't with the 34.
On the minus side: I was using a JMCK IWB #3, and draws were pretty quick, but couldn't match my usual speed with my gamer Blade Tech Black Ice. As well, I was using Ameriglo Operators on the 19 instead of a Dawson FO, and I dropped a -1 on a target array when I lost the front sight. As well, there were some difficult distant targets obscured by no-shoots, and it felt like it took a few 0.1ths longer to get an acceptable sight picture with the 19. Totally subjective of course because it always feels like forever to me to break a tough shot.
On the plus side: I just love how the 19 feels in my hand. It's my favorite gun, and it's what I carry. I can transition faster SHO and especially WHO with the 19 than with the 34, and there was a long stage of that at this match. As well, I found myself shifting to SHO to deal with some tight cover problems. So, using the 19 seemed to bring out some new IDPA tactics for me. I may keep shooting it for a while just to see where it takes me. (I'll be using my G34 for USPSA of course!)