For 2D animation, 12 frames per second is the norm, right?
Most of the major TV studios doing animation do 24 fps but animate on twos, so its effectively 12 fps. Worth keeping in mind that they normal mix and match as needed. So for most things it might be 12 fps, but that one dramatic action might be drawn on the full 24 fps.
If it were 3D, I'd say 12 fps might look choppy, but with 2D and the use of smears I think 12 fps can look really good.