I took the beginner's class in Cincinnati. I play fiddle and C#/D box, but not the concertina, and almost all Irish.
I also listened in, while my son and assorted friends, new and old, took the intermediate.
Brian is an outstanding teacher. He covered an amazing amount in a short time in both workshops and handled a wide range of students deftly. My impression is that everyone came away with much to think about and work on.
Anyone further down the tour who is on the fence-go for it. Just hearing him play and discuss the style is worth the price of admission.
Dan