Does anybody have experience with both systems enough to compare them?

I'm currently using ifupdown on my Debian server as that's the default, but it seems that the modern way of managing the local network is via systemd-networkd so I'm contemplating putting the effort in to migrate.

Would those of you who have experience with it, recommend it?

In my short investigation, I have made the following observations:

• using networkd means you can use networkctl to manually control the interfaces which is quite convenient
• networkd aims to be fully declarative
• networkd separates the creation of virtual interfaces (netdev files) from their configuration (network files)
• networkd doesn't support all networking features (e.g. namespaces)
• networkd is systemd, but surprisingly I can't find information on how to create other unit files that depend on the individual network files going up or down, other than networkd-dispatcher. I don't like dispatcher because just like ifupdown it triggers all the scripts and you need if tests to exclude all interfaces you don't need to be affected. I'd like to write unit files that can be targeted to activate and deactivate when a particular interface goes up or down.
• networkd, other than via dispatcher, does not seem to support adding arbitrary commands to run like ifupdown supports via e.g. pre-down, post-up, etc.