They use really light high quality forgings for their pistons, Ross is one of their usual vendors I believe. Their cams have logical ramp designs so they maintain reliability, good stuff. Their pipes aren't real flashy but they work really well.
I bought my first Powroll parts about 30 years ago while I was trying to turn a 1970 CB100 into a flat tracker. Good designs from a group with about 40 years experience tweaking little Hondas is tough to beat. ;)
I've got their stroker kit in my DRZ125. It is outstanding. Turn around time is quick, the advice is good and the service excellent. I don't think I would buy anyone else's small bore four stoke equipment.
We also got a stroker crank from Powroll ( for my son's CRF150 ). What a HUGE increase in power. Good qualtiy workmanship, too. We put a big bore piston in his XR80 last year, got more power, but not as extreme of an increase as the stroker.