In my opinion, Joanna Moore's character is far more interesting than Helen Crump ever was. She seems a lot stronger and sings great. Andy made a mistake letting this one go.
With Floyd teasing Andy about a wedding trap being set for him (Barney is out of town. If he'd been there he'd have been doing everything in his power to get these two kids together!), there is a certain fear and that Andy is going to be turn on Moore's character and accuse her of trying to get him to marry her. The tension as we wait for this scene to come is undeniable. Instead its a relief when Andy does not confront her and instead decides to just enjoy. Perhaps he learned from all those embarrassing relationship scenes he had with Ellie. Unfortunately Moore did not return as the series wasn't quite ready to give Andy a regular gal pal.