Yamada-kun to 7-nin no Majo is a high school *romance, with craaaaazy supernatural powers and 0% harem. It's a good time, and I enjoyed it.
The story is pretty good, in my opinion. It's focused on its central goal of building the romance with the powers playing a role in moving this along. It is at its heart a romance story, not a supernatural one. There's also the added benefit of completely avoiding the harem trap. I feel like they have to rush the witches, though, given their twelve episode run.
The art's nothing particularly stand-out, and is overall pretty generic. The character designs are
fine, with each character standing out from one another pretty easily. Pantyshots inbound, though.
The voice actors are great, the music's alright, but WOO the opening is awesome. Seriously, I love the opening, I listen to it on my own all the time.
The characters are all fine, and there's not TOO much troping (though the main character is an idiot, and the student council rules the school). We don't get too much development of the other witches, though, which is tied in to the rush that the episodes required.
I've become something of a sucker for romance anime, so I was pretty hype for the entire thing.