So, thanks to a lot of hype, I ... acquired this anime and watched it all in a couple of sittings. I'm a real sucker for anything that revolves around music and the fact that this is directed by Watanabe Shinichirō (director of Cowboy Bebop, Samurai Champloo, etc., who is known for blending music in really well) with music taken care of by Kanno Yōko (who is a bloody legend), is about as big a recommendation as any anime can get.
As expected, I was not disappointed with either the animation or the music and the "feel" of the series was very good. However, the coming-of-age storyline, while off to a promising start, dwindled into some hopelessly dull tripe full of misunderstandings, love pentagons, and a weird Christian angle. It also ends really abruptly.
While 'Kids on the Slope' might certainly be worth the watch for the music alone, it failed to deliver on all its promise and fell well short of expectations.