The first single, the one they played to death up here a couple years ago...........
There isn't any complex time signature to it. It's just a collection of bluegrass licks strung together.
Maybe they come across better live, I don't know.
The Hot Buttered Rum Band was another one I heard raves about. I got one of their shows off internet archive, I think it was the Great American in SF CA. They sounded great until they started singing. Worst harmonies ever. i couldn't listen to the entire show. It was painful.
Sorry, but it's not very difficult to imagine some of these acts being put together by focus groups or something. About 10-12 years ago they were trying to market this music as "Americana". Now it's crossover country or something.