On my personal 229, I have the short reset trigger and a GG PSAIT trigger (I think that was the acronym, it's no longer on their website, something newer is now). It made a huge improvement on the 229's trigger on the reset.
My new to me 4516 DA/SA trigger is a little nicer in both DA and SA and the reset is really nice and SHORT. It's not a PC and I've not handled a PC 3rd gen Smith. I can't say for certain that it is stock, but it feels a little better than my 4013TSW that I got New/Old stock. My 4013 only has a few hundred rounds through it. The 4516 looks new inside, but I just don't know for sure. That is my experience if it helps at all...