As I often say about the less-than-stellar episodes of the show, there's the germ of a good idea here. For one, using the frame story to comment on the silliness of the show's narrative conceit with Kevin the therapist constantly asking Robin to get to the point while she delves into a mostly-unrelated story about Marshall and Lily is a cute plot, it's just not especially well done. Kal Penn in particular joins the pantheon of people like Jennifer Morrison who are perfectly good at what they do, but don't really fit in with the show.
As for the rest of the episode, the Marshall-Lily-Ted bit about Ted getting too involved in their pregnancy and being a third wheel in general had a few good laughs (especially the photo montage at the end), but it had a weird message about not being skeptical about doctors who just tell you what you want to hear, especially when Lily shuts Marshall down about it. (Ted's obviously goes too far.) And the whole resolution of it is pretty strange.
And here we go with more of the whole Barney-Robin-Nora love triangle as the show goes headlong into super broad comedy and relationship melodrama. Barney's various schemes are even more outlandish than usual, and Robin feels out of character. Gone are the mostly real characters we knew and loved (Robin more than Barney) and in their place are caricatured duplicates whose every romantic trial and tribulation we're supposed to care about despite dull obstacle love interests in their way and their general incompatibility and jerkish behavior to one another. Sign of the times, especially Robin's trying to steal Barney and Barney's obliviousness about the whole thing.
(Oh, and if I'm not mistaken, this is the introduction of both Robin crying under the desk with a bottle of wine, which has been meme-ified to the extreme, and the running bit about Robin being unduly harsh with Patrice, which is probably my least favorite continuing gag on the show.)