Another thing, that helps (not with the share but with the content) is access based enumeration. If you define the ACLs in a way, that only specific people can access that directory, ABE enables you to "hide" all content which is inaccessible for the user. This enables you to a) don't give more informations about other directories to the user, which he can't access (which is no security at all, but helps you with the userquestions "hey why can't i access Project ABC? Something is broken" b) increase user satisfaction, since it is really frustrating to navigate through directories without having access to half of the folders  So the only way to get it secure is using ACLs. Best is follow the best-practice of "whitelisting" and try not to use "blacklisting" (deny-ACLs). In combination with ABE and hidden shares you can deliver a secure (to a point..) and userfriendly environment.
New  to isilon here. Is there a way to hide a SMB share from users, other than root/administrator?   thanks
Hide a share