These two are great together. The show started off with Lucy doing a set, then bringing John on for her last number. Then John did a set, bringing Lucy on to end his set. Then there was an intermission. They both played with each other in the second half. I don't know either of them well, so it's hard for me to say if John's schtick is an act or really him -- he forgets where he's going, makes fun of himself, has more capos than one guitar should have, etc. But whatever the reason for his behavior on stage, he's very enjoyable.
Lucy is a fine singer-songwriter and able to hold her own on stage. But they played off each other very well.
If you get to see them, either together or alone, go!