For common rail nozzles....... go with the reputable companies that have been mentioned in this thread.
Honing is an art, just like edm. Different medias, different ways of measuring flow, etc.. How far you can hone out with certain methods... all play a role in cleanliness, power, burn time, cloud point, etc.... Which is the reason why I said what I did.
I'll only use 1 company for my 12 valve stuff, due to the media, and how we work together.... with number of flows with certain designs of nozzles/spray angles, etc.. but I wouldn't use him for common rail stuff.