This was a classic How I Met Your Mother episode like the ones we were used to in the first few seasons.
There was (finally) a theory again, one of the features that make this show so epic in the first place. Things like the olive theory, slapsgiving, the bro code et cetera. I really miss these elements.
I also really enjoy the twists and turns that change and evolve according to the storyteller's memory, like in this episode, when the background of the fight between barney and lilly is slowly but surely revealed.
Finally, the intelligently humorous scene with ted and the captain definitely stole the show, rivalled only by the closing scene with barney and marshall as pirates. All in all, a great episode.