I too am in the same boat and couple that with an exchange 2007 upgrade comming.
So far symantec told me dfs works, exchange individual mailbox restore works, and everything is quick and painless.
So far I've found, DFS doesn't work, exchange indiviual mailbox restore doesn't work, and everything I've done has required more reboots and upgrades than I can afford.
If it wasn't for the fact that I'm still using exmerge, ntbackup, and have a backup 8.6 server sitting in the wings waiting I'd be paniced by now. So much for paying big money for a product that supposedly works.