Preference (for me) would be the Geddy (MIJ or MIM even) over the AM Special Jazz. The AM Special neck is thinner than Fender's usual Modern C, but it still isn't as "fast" as the Geddy or as thin. On the plus side, you get a BAII bridge (+$60 profit on resale if you don't like it), the 70s bridge pup placement (more growl and a bridge cover will completely hide it), the bound and blocked inlay neck (pure sexy), and a glossy neck (easily fixed by rubbing steel wool if you don't like it).
The AM Special has a regular bridge pup position and a Greasebucket tone system which people are VERY mixed about. Some like it, some hate it, and others don't even play Fenders and could care less about it. Try before you buy, but if you must buy blind, get the Geddy - USED!
Fender Active Precision Bass Special