This is possibly the worst episode this show has ever done. Any episode that features Robin in a leading role is asking for trouble. Cobie Smulders is attractive, however she is not funny, and her scenes here are painful.
Plot In A Paragraph: Robin is excited about seeing her first boyfriend, Simon, who is coming into town for a visit. Robin wants to prove that she's done better than him since he dumped her ten years earlier. It is obvious to Robin's friends that she's done better. But Robin, not seeing what the others do, falls head over heels for Simon all over again. And Barney makes it his mission to find Robin Sparkles' second music video which Robin had never mentioned previously even.
Even the end with Barney and Robin hooking up is not enough to save the episode.