I would like to use folder redirection for two reasons...
The first, and interestingly the least important reason, is that some of the users will be switching from XP and Vista workstations with some degree of regularity. If the profile directories are different (which, it would seem, is the best way to have it) then when they log off the XP machine and log into the Vista machine... *bing* some of their files will have disappeared. Redirect their "My Documents" (and the like) to consistent shares, and ensure they are redirected to the same place on both XP and Vista, and the issue is resolved.
Secondly, and (for me) the most important, is that some of these profiles will be pretty big. As far as I can tell, both XP and Vista are pretty dumb in the way they handle them. They won't simply copy over the parts of the profile that have changed since it was last seen... it will copy over the whole bloomin' thing, even if 99% of it already exists on the local machine... and then copies it back to the server on logout. Redirect the crucial folders to a network share, and they don't get copied at all. Bonus!