My MIM Jazz is wonderful. Admittedly the neck socket appears to be a millimeter or so too big, but it sounds good, the bridge is straight, the frets are fine, the electronics work as well as you'd expect, the pickups are on straight and the finishing is also very good. Never had any problems with it.
I've played a couple of MIA jazzes, and while they certainly sound better (in my opinon of course), I'm not particularly convinced that the construction's better than the MIM and justifies the extra 3 or 4 hundred quid.
I would happily buy another MIM bass. For the right money of course
Truckstop