While the moments with the 3D animation are bad, and the first minutes of the first episode are painful and misleading, I am enjoying the anime a lot. This is not for Uta*pri fans, it seems (I am not a utapri fan), but if you like Kimi to Boku, you might like this one. It felt like Kimi to Boku + B-Project to me. I would say it is mostly shoujo or slice of life, the episodes are usually just the 4 young boys in school, and sometimes in their idol life. There almost is no reason for them to be idols. And most oftheir idol life consists in doing commercials and novels, not really singing.
They are not in an idol school, by the way. And they already met before the anime started, even if they were not close friends.

The ending is different every time, and that's where you get the songs, dances, and good animation. I don't think the overall animation is bad. It is more that it doesn't need to be so good, since they are usually doing nothing.

I thought of it as campy, charming, really really funny, and worth it. And while I agree the characters could have more... "Character", I've seem worse in my idol anime search.