I have an environment with 7 S-660s in production and 7 in dev. There is a M-1060 for each cluster of 7 so that is how we're synching configurations. The active configuration on the Prod cluster is pushed to the dev cluster via a manual process. Even though my environment is using the 1060's for Managing the WSAs, the process is the same for WSA config to WSA config.
Download the configuration, don't forget to uncheck the 'Mask Passwords'.
Upload the configuration to the other WSA and BEFORE committing, you'll have to change the IP address, hostname and a few other configurations. This will get all your Access Policies, custom categories synched between your WSAs.
This only works between WSAs of similiar AsynchOS versions. I have not tried it or can confirm going from S-650 to S-160 or from, say, 5.7 Asynch to 6.0.
Good Luck.