Without a lot of micro-analysis, I gave it a "7" (Good). It was reasonably entertaining, sweet, charming. Other than the musical band element, it was a relatively generic "girls come together as a team" story with fairly stock characters. The voice actresses worked very hard to give each character sufficient personality. Mio was relatively unique in that she seemed to be an amalgam of Kagami (L*S) and Motoko (LH).
Probably the funniest part of the series for me was Sensei's backstory ("too far")
Following up was Yui and her idiot-love relationship with her guitar.
Points for Mio's channeling of Darth Vader with her grip and Deathstar amplifier.
I've watched each episode twice now ... it does have some rewatchability and my opinion of it improved on the second viewing.
I've decided the profile singing shots of ep 12 are *not* "bad animation". Pull up some live video of female japanese rock singers and look for side profile shots (you'll find very few) -- they tend to jut their lips forward like that (Kotoko immediately comes to mind as I have a collection of her live performances).
I guess my major disappointment is that given this is a KyoAni production about a girl pop band... I'm still expecting more music video performances. Think of the old Monkees tv series (they had a song at the climax of every episode). After all, nothing stopped KyoAni from spending part of every episode in L*S with the anime-only L*Channel.... Still, what we got was fun and I'm planning on picking up the OST.