I bought one of these on the 'Bay' and just put it on my parts J in place of the BA II.
http://cgi.ebay.com/ws/eBayISAPI.dll...m=140389588115
The bass sounds better than it ever has: much warmer and rounder. The bass is a maple topped alder body with a rosewood fingerboard, Barts into an Audere and for the last five years I have fought a zingy tone that I attributed to the maple top. Nope, the BA II was the problem.
I put a set of the brass saddles on my fretless and got more warmth and a bit more low end, so I spent $16 on the whole bridge for its fretted sibling. Best $16 I've ever spent.

As an added bonus, the bass is about a lighter. Something to think about.