I have a g23 g4 and love it. I think the best things I have done to it are really simple. Extended slide release and 3.5 lbs trigger connector. I am still getting use to the lighter trigger, but it is not too much lighter.
Welcome! If you are going to get a connector then you might as well get it polished with the reduced striker spring and plunger spring aswell and a competition trigger spring.....glocktriggers.com sells all this as a kit and its the best money I ever spent!!!