I ran cjdns for 5 years but recently switched off it. For one, it seemed to have too much traffic over my limited outbound link when things should have been more idle. Also, the commit logs were a little unnerving to me for code I'm trusting with my network security:

All kinds of "oops" edits: https://github.com/cjdelisle/cjdns/commit/3abe50b8e744f72696... https://github.com/cjdelisle/cjdns/commit/feabb1970fbaecf65c... https://github.com/cjdelisle/cjdns/commit/c51d89431f1fa42955... https://github.com/cjdelisle/cjdns/commit/1b0c999bd2e5988c3f... https://github.com/cjdelisle/cjdns/commit/355d7d77cc82c52bf1... (function args passed in the wrong order)

Some are about extra traffic: https://github.com/cjdelisle/cjdns/commit/8bcfbf227a87020931... https://github.com/cjdelisle/cjdns/commit/0ee9cb7f45b466232b...

Also it's ipv6 only, which took some fussing. Performance was fine, even on rpi. Reestablishing links was slow and sometimes required restarting of the daemon. Daemons would occasionally get wedged. Log output is unconventional and uses a special reader tool (a la adb for android). Occasionally routes wouldn't be chosen right (two home computers would route via an external cloud box), which I'd fix by restarting the right daemons.

I laboriously switched to openvpn (two networks) and haven't worked out all the routing and hotswitching for my roaming phone+laptop yet. Now I'm considering vita, tinc, zerotier, or wireguard. Probably I'll try out zerotier to see if it works out of the box, then try wireguard if I'm going to have to configure it a lot, since it seems like WG is the most unix-toolbox-do-one-thing out of all of them.