This episode is a an okay episode. The bulk of it is Lily and Marshall fighting regarding Lily's need to "make a mistake" and Ted trying to bag Robin (which is pretty much what we've been building to since episode 1).
My biggest sadness is that Barney doesn't play a larger role in this episode. His character really takes a backseat, which is understandable since the episode already has two major plot lines tying up, but his lack of involvement makes the episode less than stellar.
At about 15:00 into the episode, Lily and Marshall are having dinner and Lily begins to cry. I don't know if it was intentional or if Alyson Is just not good at crying, but her crying is overly animated, almost cartoonish and really ruins the mood of the episode. Alyson continues to cry like this throughout the series and it becomes more and more grating ever time she does so.
TLDR: overall good plot pushing information, no Barney, bad crying on Alyson's part.