Four albums in, and Punch Brothers have come a long way from their beginnings on Chris Thile's "How To Grow A Woman From The Ground". On their previous outing, "Who's Feeling Young Now?" the degree to which "bluegrass" was a valid term was lessened considerably. With "the Phosphorescent Blues", the tag seems utterly redundant, as does every variant thereafter ("Prog-grass" being a favourite … horrible terminology indeed).
I'm going to leave aside all references to the fact that Punch Brothers are a technically gifted group: their mastery of their instruments is unquestionable. However, I will say that these technical skills can make for a somewhat tiring experience: the endless cascade of notes, even when slowed, makes for a lot to absorb. There are only so many counterpoint arpeggios that the ear can take before you long for Peter Buck's simplistic eBow playing. That's enough of that.