Oh God this episode was awesome. One of my favourites of the BW series so far, even if I was very annoyed that Satoshi's Butterfree wasn't going to appear and predisposed that I wasn't going to like it. But there is actually no thing that I didn't liked about this episode except that the flashbacks may have been a little longer.
The animation wasn't so terrible as it seemed by the previews, Musashi and Kojiro were weirdly drawn, but the other comical scenes combined with the animation were pretty good, and it was a long time without seeing Satoshi providing this amount of comical scenes, along with Team Rocket making up a plan so simple like they used to do long, long ago. A Trancell with actual personality is a plus.
I'm not a very nostalgic person when it comes to Pokémon, but I almost cried not only at the end, but specially when I heard a bit of the Tabidachi (Set off) music playing in the background, not sure why. Also, it was nice to see Satoshi crying again since for me he has looked like a personality-less character several times in the BW series. In my opinion, the episode was so great that I completely forgot how bad I felt when I learnt that his own Butterfree wasn't going to appear.
The anime staff managed to prevent themselves from ending an episode with their typical sunset scene that they are so fixated with.