Backup Exec is cheaper than NetBackup. NetBackup scales bigger and better than BE. I would imagine that the performance limitations would be imposed by your hardware, rather than the software. Exchange, SQL and Oracle are all supported on both BE and NB. BE can be installed in trial mode, so you have 60 days to see whether it meets your needs.
We are backing up mostly virtual machines, about a dozen servers, at this point don't see expanding beyond the one library we have, and even if we do, no de-centralized plan in the works. We do not have multiple master servers. We do have remote boxes but they are running Backup Exec, thus the question if we can consolidate to a single app. that would make management much easier.