I signed up specifically to reply to this topic, that is how strongly I feel about the Vintage Jazz copy.
It was my first bass, and still my favourite even though I now have a Fender Precision to call my own. I love it, the neck is fast, there is a surprising ammount of grunt to be had from the pickups, and they can do anything. I am an indecisive bassist, my Jazz puts up with Red Hot Chilie Peppers style slaping, Funeral For A Friend type rock (it does really well here), and Muse style "guitarist countermeasure" fuzz.
Simply put I love it, it sounds great and plays great.
A caveat though. It doesn't feel as solid as the Fender, it plays and sounds better, but it doesn't feel like it could stand up to the abuse the Fender could. So maybe it would be worth looking into the Vintage Advance basses, as I assume they will sound failry simillar (and they carry a cheap price tag), but they are built to higher specs, plus you can get one in white, the EJM is only black or sunburst.
Sam
EDIT: I've gigged with this bass for three years, I know it can stand up to the life of a working bass, it's no fragile toy, but it just doesn't feel like you could beat a groupie to death with it and then carry on playing, unlike said Fender.