Well, to be fair they did mostly Joe's songs & Daryl is more of a vocalist than a guitar player. Daryl has an amazing voice & is a great songwriter as well. They have different talents. If you watch the series, you can see that Daryl has loads of talent. I think Daryl & Joe would write something incredible if they do work together, which it sounds like Joe wants to do.
The show is always geared to feature the guest artist....Seems like Joe & Daryl got along well because prior to this they hardly knew each other.
They also look pretty darn cute together! LOL