I got lucky and found an S2 Orange for a really good deal. I should have it in hand next week. I'm in no rush to do anything to it since I haven't shot it yet but I'm pretty positive I'll make a few small changes.
I'm definitely getting LOK thin grips. They suit me better than anything else I've seen.
Next I'm probably getting some stuff from CGW. An extended firing pin & firing pin spring, the music wire 11.5# hammer spring, reduced power trigger return spring, and a floating trigger pin. There's a few other small things I may eventually consider like a reach reduction, Dawson front sight, etc...
Besides this short list is there anything else you guys would add?