The sequel to the all-conquering K-ON is surprisingly different from the original. Certainly not Futakoi Alternative different, and not even Kanon different, but still very much different. The direction was squarely aimed at extracting maximum from the "cute girls doing cute things" angle and extremely deliberate. Remember how Azusa was retrofitted into the OP in the classic K-ON — very poor planning. Nothing like that was permitted this time.
Creators stepped outside the rigid mission rules only when the success was essentially assured, and so the direction became cinematic in the graduation episode. Note that crazy dream overlaps of ep.13 are not the same thing!
Technical quality was outstanding throughout. Obviously, no crooked fingers. KyotoAni's trademark motion occured periodically (e.g. early on, there was a moment where Ritsu made "wah, surprise" movement). Detail was lavish. Ton-chan moving always, 3D blended in masterfuly, backgrounds, the works.
New characters did happen, although in a sneaky way: Nodoka, Jun and Ui were given bigger roles than before.
Liked: Not as much as the classic K-ON