My environment is very large and we use Netbackup to backup a lot of servers and it works well, for the most part. One concern I do have is that we use a VTL with de-dupe and that means that you can't use naitive SQL compression when you are backing up large databases. This causes more of a network bottleneck.

Another concern is handling failed backups as the database backups are spread across three teams. Windows Admins load the Netbackup agents, DBA sets up the SQL agent scripts and the SAN/UNIX team schedules the jobs. It can make root failure analysis difficult.