In action, there's little difference. They both shoot the same as far as accuracy goes. PPS ends up with less barrel since they add a full size bolt and move the feed up the barrel an inch and a hair.
I can built them with vertical air without extending the lower tube.....PPS doesn't.
I have been using the same type of trigger system, but have changed over to a simpler, smoother setup.
I try to be more flexible in the options I make available, while PPS has a pretty set-in-stone regimen regarding mods they'll take the time to do.