I agree the middle of the show is not that great, but it is important in establishing the characters for maximum effect.
My friend Ping Pong at its best is second half of EP1 and the last 2/3 episodes. I think the way those episodes re-contextualize all the characters and the work the animation and storyboard do to deliver the themes is brilliant. But that only works after seeing them. I would go so far as to say EP 10-11 are some of if not the best episodes of Anime ever made. I agree the middle of the show is not that great, but it is important in establishing the characters for maximum effect.