I got rid of my Fenders and Laklands a few years ago, and stuck with my two CV's until it got a Vm PJ (which I never really got on with). I also got a Yamaha 5 string (that I'm going to get do of soon) a few months ago but that's a totally different bass so doesn't really count.
I had a bad time trying to get a perfect (to me) finished MIA a few years ago. In fact I started off with a MIM 70's Classic, went on to 2 MIA jazz basses and finished with a Highway-one. Every one of these basses had quality issues (first and last had raised frets). During this time I had a perfect CV Jazz but thought getting a MIA or a MIm would get me something a bit more. It never happend, although I would have been very happy with the MIA if the build quality had matched the price.
For me though it's the CV necks. These are slim, have vintage frets and just feel so comfortable. The CV Jazz neck has been on 3 different basses, I love it that much.
I can appreciate the better features on the MIA's, but these aren't must haves IMO, just icing on the cake.