However, we have had a very difficult time making our WebDAV configuration work with AD. We kept having a problem with folder permissions. Either a user would get full access to every folder, or they wouldn't get any access to any folders. Which is kind of a big problem.
We found that the key is to install and configure your WebDAV server on the file server that is housing the network drive you want to give access to. When you set it up this way the WebDAV server can properly managing the permissions. If it is on a separate server you will continue to run into the permission problems.
We actually plan to expand our WebDAV use outside the iOS application. We are planning to use WebDAV to provide access to all user drives when they are away from the office, and do away with the need for VPN access.