I had them make a barrel for me this past summer, .54, 1-66" twist. The barrel flat out shoots. It is a very accurate barrel, haven't really found too many combinations that it doesn't like. They were very friendly and easy to work with. Turn around time was about 2 months.
The cons. The barrel exterior was very rough. If you think Green Mountain barrels are rough looking on the outside, this is nothing. It took a lot of polishing on my end to get it ready to blue. The end of the barrel didn't have that "finished" look. No chamfer at the end, just cut off square. No stamp on the barrel at all for caliber or twist, not even a makers mark. Breech plug did not have a clean out screw in it.
I am thinking of another barrel from them next spring, and the cons are issues I would address before I go ahead with it.