DSBass,
I've just done a couple of posts about this bass, but I was actually going to get an American Special P as a second to my '72 P. I wanted the narrower neck, and a sound to compliment my other bass.
The American Special has a very nice neck and is fairly light. But to me, it sounded kind of 'hollow' and 'cupped'. It just wasn't giving me the 'oomphf' I wanted; even seemed to be missing the extended frequency range that I know a P can have.
I played a number of basses over several visits, including the American Standard P, other '50's replicas, and some $2K basses. Then I tried the Nate Mendel. Immediately the neck felt familiar, like it was the neck my hands wanted to play. And the sound was all over the American Special P. Stomped it, to my ears. The tone control is apparently carefully designed to roll off the treble without affecting the bass, but I felt it made almost no difference to the tone.
Here's the thing: I traded an EBMM Sterling for the Nate Mendel. I love the MM basses, and the quality of them, and a small part of me expected to get a MIA bass (if a Fender), but the NM is a killer. Or at least this one is. Straight out of the box it was perfect. I love it so much, I'm typing this one-handed.
It is hugely better made than my '72 MIA bass, and remarkably close in sound quality. Big, fat, full range, great sustain. Certainly brighter than the P Special, to be sure, but there is also more bottom extension and fullness; almost like it is revealing more of the sounds. To my ears, at least.
I'm over worrying about MIA vs MIM; each bass is different, but my Nate Mendel is superb.
Very highly recommended.