I finally decided to watch this. I also confirm the similar atmospheric feel to ARIA, but it's a completely different one. There are a lot more characters, so it somewhat detracts from the laid back feel (at least for me). It's also more of the 4-koma vein, instead of focusing on largely a single aspect.

At the same time, I'm really drawn (heh) towards the art in the series. The backgrounds catch my eye so well, that I have trouble focusing on the subs. It's almost straight out of a watercolor. In the classrooms and cities, it's less of a problem.