6.9/10. Did we really need a payoff to the Pumpkin girl story? Probably not. It's a subtle indication that the show was running out of places to go and had started eating its own tail to compensate. That said, I really like where they went with it. It would have been easy to turn the Pumpkin into another major season-spanning relationship for Ted. Instead, the episode dealt with the idea that you can build something up in your mind based on a brief encounter, and that the fuller experience reveals a lack of a real connection. The twist that for most of the episode, Ted wasn't feeling it and thought Naomi was kind of nuts, only to find out that Naomi wasn't feeling it either, but was equally trying to play up to the moment since she too had built the potential for their relationship up was a nice way to illustrate that.
The rest of the episode didn't quite measure up. Lily having "pregnancy brain," which rendered her dumb had some amusing, if fairly stock humor with her forgetting words and handing out staplers as Halloween candy and whatnot, but the whole premise is super-broad and a symptom of the increased cartoonishness of an already decently cartoony show. Still, the metaphor of pregnany Lily as a drunk girl that Marshall was trying not to take advantage of, while Lily tried to "seduce" him with a house in the suburbs was worthwhile premise, even if the way the show went about it wasn't as sharp as I might have liked.
Robin discovering Barney's Canadian heritage and rubbing it in his face was definitely the lightest of the stories in the episode, but chuckle-worthy enough. Robin ribbing Barney about it as payback was entertaining, and Barney's Rocky IV reference in lieu of donning the Mountie costume was pleasant if, once again, pretty cartoony. The end tag with Barney fighting the Canadian version of himself was a bridge too far though.
Overall, some decent laughs, and a nice main story, but a lot of hit or miss stuff at the margins.