Depends on your choice of cart - the detachable shell version is higher mass, and likely to be more at home with modern carts. The fixed shell version is very low mass and really only suited to the high compliance MM carts of it's period e.g. Shure V15III, Ortofon VME20E etc, though that's not to say it doesn't work with other carts - I've actually heard a Sumiko BPS MC cart sounding pretty happy in one. If you are planning to swap for a detachable shell 3009 I'd go for the pre-Improved as it's a better arm IMO and can be found for not much more second hand.
Tony.