IIRC the audits have been a benefit of MOCs since they were implemented. It does prevent non-members and non-paying members from obtaining the coordinates and other information of your cache.
Remember, however, that more people than are listed in your audit have access to your cache information. I as well as some other cachers rarely visit gc.com's cache pages and obtain our information via Pocket Queries. Of course, in theory only paying members can get PQs.