What's the difference between SafeNET and BungeeGuard?

Answer to this frequently asked question.

The use of custom login results to forward plugin data to backend servers was inspired by BungeeGuard, although was perfected to properly handle edge cases and wide selection of server software implementations.

You can't go wrong with classic BungeeGuard, however, if you would also like to use the IP-whitelist, this is the way to go. The plugin also supports GeyserMC (including Floodgate), which other plugins do not. Logs everything to the console for easy verification and control over connection flow.