I'll say here what I've said elsewhere - every modification you make to your competition pistol needs to be done with a specific purpose in mind. Tinkering with your guns 'just for fun' is a waste of time and money that could, and should, be better spent on ammo.
Also, remember that the equipment rules for USPSA Production are basically,
"If it iz not mandantory, it iz forbidden!" In particular, moving any metal (or plastic) is verboten, unless it is for a purpose specifically covered in the rulebook.
Here's the rulebook, Production equipment rules start at page 77.
But anyway, you asked what I do to my Production/SSP guns. So here's my list:
1.) Take one recent-production Gen4 Glock 34.
2.) Install a Lone Wolf 3.5# connector. ($15)
3.) Install a Wolff extra power trigger spring. ($3)
4.) Install a Glock Gen4 extended 'FBI' magazine release. ($4)
5.) Snap in a Glockmeister Grip Plug. ($7)
6.) Install a set of Warren Tactical sights, plain rear and fiber-optic front. As an aside, I've had the best luck with the 0.245" front sights on the long-slide Glocks. ($77)
That's it. Go shoot!
There are some things I'm going to be experimenting with in the near future - namely, I want to try an internal overtravel stop of some kind, to see if it helps with my long-range accuracy. I'm also thinking about having a Bar-Sto barrel fitted, same reason.
-C