I probably polished a few areas that didn't need it, basically if I saw worn metal through the finish I polished that area.
I always cold blue the exposed metal for rust prevention so I didn't mind polishing a couple extra areas. I didn't want to have to take it all apart again if I missed an area.
The difference is substantial, before polishing I considered my PCR to have a pretty good trigger now next to the P01 it feels gritty.
This is why I sometimes avoid doing trigger jobs, once you do one it makes everything else feel like junk. I have to go through and polish everything else in my other guns now. Oh well, I'll likely wait until I get some Cajun Gun Works parts to do at the same time.