Deeaa, I agree with you that the neck makes or breaks the guitar and so your points about the fret/neck quality of the imports seems very reasonable. I'd guess that the fret material is probably the same stuff on either MIA or import, but maybe the wood quality and/or finishing processes may have a significant effect on the stability of the frets.

FWIW - I recently played a CV jazz bass when I was auditioning amphs and was very, very impressed. This particular one had a nice flame pattern to the neck and very low action - even in a Guitar Center!