It's not unusual for Domino servers to have bloated System databases that never seem to get compacted/maintained because it's just always been a hassle for many admins to shut down and manually do it. As a result, these databases are often neglected, missing out on needed regular maintenance, so they can get pretty huge and can often respond sluggishly when they do need to be opened. Usually with many GB of disk space trapped inside they are just wasting disk space too, it all adds up costing time and money, not to mention it can be aggravating for admins and users when they do need to work with these databases.
This feature in Defrag.NSF+ makes it so easy to apply best practice maintenance, get these compacted back to an optimised size, free up space and give Domino a nice scheduled "Health Restart".
Defrag.NSF+ makes this as simple as ticking a few boxes, set and forget, and if this is scheduled once a week the difference this can make to Domino is significant..
As an added bonus, those Domino System DB's also got an ODS upgrade during the process.