For: Simplicity, effectiveness, potential.
Against: Deployment will need to be thought through carefully.
Verdict: An extremely useful tool for administering access control within mixed environments.

The local machine effectively becomes an Active Directory client, regardless of the operating system platform. Implementing this model is fast and easy once the central management tools are in place and consists primarily of installing the local agents and thinking about how such access permissions might usefully be grouped. This latter issue is addressed by the concept of DirectControl Zones, which allows the administrator to configure logical groupings across platforms, organised by department, role or whatever best fits the organisation.
Centrify DirectControl offers additional possibilities, including the provision of web-based single sign-on for internal and external users. However, the access-control integration across Windows and other environments alone is reason enough to take a serious look at this product.
The intention is to simplify this from both an administrative and regular usage perspective, and it is apparent that Centrify has realised this objective. Furthermore, with the provision of a logical and intuitive administrator console and integral reporting facilities, a wealth of information is readily available around access permissions and zones, ensuring that you are always up to date with the access control position within your organisation.