DFS as a physical location for an IIS site

From iis 7.5 (at least that's when I know it's possible), I can use the dfs share (like \ websiteshare \ Mysite) as the physical location of the IIS site.

For example, in a web farm environment, we got 2 or 3 servers, and the site is a CMS that supports some content and files.

The obvious reason for choosing to share dfs as a physical location is that when an editor downloads a file, it will be available everywhere.

I'm wondering is this a good idea? I always thought dfs was slow and not very good for hosting an IIS site.