The Brian and Stewie plot were pretty enjoyable and I was surprised as to how it was played straight. I did get a laugh out of all the things they said and did in the vault, and how those two actually care for each other, despite giving each other a hard time every chance they get.
As for the musical numbers, wished they showed some more of them, but I did end up liking "Got a Lot to See" "Sheboopi" and "Drunken Irish Dad" definitely some of my favorite songs during FG's run.