Only drawback I have heard is the safety works backwards. The early ones with the peep sight in the rear scope bridge are neat. Also they came with two different triggers (set and standard) which are hard to find if you want to change to the other type, and IIRC no aftermarket triggers are available.
Ask over here-
http://www.bigbore.org/index.php?op...=3&func=view&catid=9&id=1016
there seem to be some using them.