Congrats on the G23. That was my first gun, and I have yet to even imagine regretting it. It's been faithful through daily carry, torture tests, and various other elements no gun should endure... but it's running along like the day I bought it... LIKE A CHAMP
As for break-in period: Some people are going to tell you that there is no break-in period for a Glock; Some will tell you it only applies to the magazine; Some will tell you you should have shot one, let the barrel cool, shot two, let the barrel cool, and so-on; And some will tell you to shoot 1-200 factory rounds to make sure there are no problems, then you're good to go. I'm not too sure there's a right or wrong way to do it. Whatever you're good with should work just fine. I don't think I've ever heard a Glock owner say, "Man, this thing wasn't broken-in correctly."
For factory rounds, I usually shoot cheap WWB or Federal stuff. My G23 eats anything I put through it and asks for more. I don't reload, so I can't vouch for how good/bad they are in that aspect. But they have yet to give me any problems. I had one bad round that didn't go off in the several thousand rounds I have shot... just to give you perspective.
And, I'm kind of
from Illinois, as well. What part are you from, if you don't mind me asking? I used to LOVE going to Chicago on the weekends and partying. Did a lot of work out that way, and in the Wisconsin area too.