Living in a non-ccw allowed country I don't always consider the potential legal ramifications of an aftermarket trigger - the only time I've carried a pistol is in an area of ops where the odds of a lawsuit where a lighter trigger would play a factor is zero. I do understand that with the current atmosphere in the USA, it could be very much the case. The 5 to 5.5ish # trigger isn't all that much heavier than the 3.5lb anyway, it's more about other factors than the weight with the improved trigger press anyway IMO.
One thing nobody has mentioned much is the sights. If you haven't tried the Vickers/Wilson Glock sights, and ever plan on changing your Glock sights, try these ones out. Excellent sights, the best Glock sights I've used, night or otherwise. I wouldn't necessarily say it's worth the $ if you already have night/good aftermarket sights, but if you have the Glock factory sights, these are the ones to get IMO.
Do any of you USA guys doing ccw use a pocket magazine holder of some kind for your extra mag, if you're carrying just a single and not using a typical belt mounted mag holder? Again, not product that has much use where I'm from unfortunately, but I read some stuff recently about the leather or kydex single mag holder that is shaped to sit in your pocket, and present the magazine in a consistent way other than just in your pocket how it ends up sitting randomly. I agree that a pistol without a reload is a terrible idea, not just for the extra ammunition obviously, but primarily for stoppage drills - a worst case scenario stoppage where stripping the magazine is required to clear it leaves one in a poor spot without an easily accessible replacement mag, as trying to retain your only magazine while working the stoppage = tricky stuff, and will slow the whole operation by a large factor. I could also understand though that doing CCW in warmer weather with a belt mounted mag holder on the opposite side of what you're trying to hide on the other (the pistol) makes concealment even more difficult overall. That's why I found the whole pocket mag holder an interesting little piece of kit.
I had a Glock 34, not a gen4, and they were very popular in the Gen3 days as well. Everybody and their dog that shot competition in the various classes that allowed it were shooting it in my parts. I still prefer the G19 if I was carrying due to size/dimensions/etc.