As explained in the journald.conf manpage, this setting forwards the logging if you have a syslog daemon running. So you can continue to use syslog.ForwardToSyslog=yes
Personally, I'm happy with the systemd journal on my not-Mint distro; it contains more information, is faster (for me) to search, and journalctl can be piped so I can grep, cut, sed, and whatnot just as I used to do with syslog files.
But as always, use whatever works best for you