I'm running an FMF Gnarly pipe with FMF's TC silencer on my KX500. Runs great, but I don't have a direct comparrison to PC's silencer with my pipe. Hard to know which is best without trying both. Good luck.
I looked at both of the main models (FMF and Pro Circuit) when it was time for one on my YZ 250. Externally, I liked the FMF model. I opened them up. The pro circuit model was built better. The fmf had very sloppy cuts and crummy welds. FMF hired third graders to weld it or were very drunk when it was time to bolt it together. The fit was not good at all.
Obviously I only looked at one example of each, but the PC model was the one I bought.
I run an fmf gnarly pipe on the bike and am very satisfied with it. I wanted to keep the pipe and silencer the same, but I could not justify paying over 100.00 for something of such poor quality.
Anyone familiar with having a lot of resin with running a spark arrestor? I usually run a bills pipe, but have PC Spark Arrestor for woods use. It seems to show a lot of resin, I am pretty sure I am running dead on with jetting, etc. 32:1 oil, maxima. I was thinking of taking out the paking, another kdx with a pc spark arrestor did this. Any comments? Thanks in advance.