This is not at all what I was expecting after watching the ONA. It is more in the vein of shows like Hidamari Sketch, Working!, and Acchi Kocchi. (Renkin San-kyuu Magical? Pokaan also comes to mind). It is an enjoyable slice of life with comedy elements. I found the climax (for which, suddenly, everything ends in fiery explosions despite the utter lack of precedent within the show) to be the most predictable and least enjoyable part.
I'm glad it is not what I expected. After the ONA I thought, "If they made a full length series for this it could be brilliant. More likely it would be terrible. It depends on whether they go the way they should go with it, or the way I know they will go with it." Instead the series is something else entirely.
I watched this whole show, which is great praise for it given my recent experiences with anime. Even if it wasn't nearly what it could have been, it is still a rare gem: a palatable title instead of yet another putrid turd for the ever-growing pile of trash.