Of the few Precisions I've had, my top 3 goes like this:
1: 1990 MIJ Squier Precision - The best sounding and best playing P bass I've ever had. All original - £100 from ebay.
2: MIM Precision - Almost as good as the above. Lovely neck, comfortable and fast. Pimped with a SDQP - £350 used.
3: 1978 Fender Precision - Mojo a plenty, lots of thump, bit heavy. All original - £800 used.
I've had a couple of US Standards, and I can't remember what they were like. That says quite a bit to me.
Back on topic.....the Mexican one was a beauty. Good build quality and easy to play, OK, I put a QP in there, but only for the sake of it really, the original pup was fine as it was. To me, like with [i]ANY[/i] make of bass, if you look around and try a few, you can find a really good example, and with the price difference between MIM and MIA, I'd go for a [i]nice[/i] MIM every time.
MIJ of course is in the mix too, but my experience with (older) MIJ Fenders hasn't been good. I had an MIJ Jazz, admitedly an oldish one, but it was rubbish in most respects, maybe I was unlucky.