Perfectly good episode, with good conceits for each. Robin's story felt a little rushed, but I liked the idea of her breaking up with (and being broken up with) a little kid as analogous to real life breakups. Plus, it delves deeper into Robin's fear of having and relating to kids and apart from the high concept hilarity of being dumped by a six-year-old, gives some more emotional depth to her stance on children.
Ted and Barney's story about trying to prove who has more "game" by hitting on the same girl is less successful overall, but still pretty funny and creative, especially with Marshall's desperate attempts to prove he's still relevant to the competition despite dating (and eventually marrying) the same woman over the past 11 years. The visualization of Ted's revulsion to going where Barney's gone before, and the reveal of Barney's Machiavellian plot to win the competition are pretty amusing in that inventive HIMYM-way, even if the mini-Barneys get kind of cheesy after a while.
All-in-all, it's not the sharpest outing from the show, but there's a lot to like, including the little moments like "every blind date has a 'but...'" conversation. Eminently watchable How I Met Your Mother episode.