Here's our review of Apple's latest Mac OS X Server operating system.
In Active Directory and Novell's eDirectory, moving users or machines between groups and containers is a simple drag-and-drop operation; Mac OS X 10.5 Server requires a more complicated multi-step process in the GUI or use of the command line.
Finally, you can't use Mac OS X 10.5 Server's administrator tools to manage Mac OS X 10.4 Server or older without upgrading those servers to Mac OS X Server 10.4.11; that limits its usefulness as the backbone of a larger network.
Mac OS X 10.5 Server has been improved in some ways when it comes to working in heterogeneous environments. Active Directory integration now allows both server and client versions of Mac OS X 10.5 to work correctly with Windows SMB packet signing. In addition, Apple has introduced the concept of "augmented" users, or users imported from other directory services.
This makes managing Mac users in non-Apple environments easier. In my testing, I found I could manage Active Directory users within my Mac environment almost as easily as Mac-only users.