We're using Puredisk 6.5.1 with Netbackup PDDO and it generally works well BUT I agree with the original poster that you should allocate a lot more storage than you think you're going to need. Adding a new content router is a reasonably well-documented and straightforward procedure, but the content rerouting job which is required after activation takes a long time (5 days in our case) and during the rerouting, backups and restores are unreliable and can either fail altogether or take much longer than normal.
Certainly not something you want to be doing on a regular basis.
