Systemd automount vs autofs

I think you've largely answered your own question.

Systemd thinks about most things in a "just in time" manager, so adding automount was an obvious extension. The configuration uses a common style, but isn't super flexible.

Autofs is the old way we used to do this. It's flexible, the config is kind of complex/weird, and it's probably not installed by default.

You probably want systemd unless your needs are complex. A simple automount setup guide is here: http://blog.tomecek.net/post/automount-with-systemd/

The main difference for me is that autofs, with the right auto scripts, will dynamically list the available shares. So you don't need to pre-define and hard-code which machines/shares should be made available.

With systemd's automount, only shares which you have pre-configured will be visible. Whether this is an advantage or a disadvantage depends on your environment, policy, use patterns etc.