Had a Vang for a few years, 870, I've never been much of a shotgun person till then. Always considered myself a rifleman..
Then a friend (Tom Mayo) managed to get me a Vang Comp, the combination of porting and back boring is true magic. It made beautiful patterns with everything... except S&B 00 Buck, for some reason.
He will be doing the barrel for my new 1100 Tactical soon too.
Personally I recommend it and him.