The couch gag was a little long, but not that much. I thought it was ok.
As for the episode itself, well, they keep using this "perfect Lisa's boyfriend boys that we'll never see again" and Marge's opinion on the subject seemed underdeveloped. I got the idea that she still thinks of Lisa as her little child and she wants to have her around or something, but that's quite selfish on her part.
Other than that the episode was ok. The jokes and even the animation were pretty decent, and the subplot was pretty funny and different. Also a nice role for Grampa in the main plot and good 'pain' gags with Homer for once, maybe cause they didn't involve so much pain this time.