Tinc 1.1 is actually fairly easy to set up - it's only a couple of commands for defining the name of the network, getting a link nodes can use to join etc. The only problem is that it's technically not a full release, so most distros don't carry it. Compiling isn't difficult (a simple ./configure && make && sudo make install), but it could be better. My only major issue with Tinc is lack of any central authority making it really niche - revoking keys seems to involve deleting them on each connected machine. Not fun.
From what I can tell ZeroTier seems nice as long as you're okay with using ZeroTier's servers for things (a curious trend I've noticed - so called decentralised services will always be great until you want to have fully independent servers). Sure, you can find github issues telling it's possible to set up your own planets, but the software seems somewhat complex and there's no documentation for it, and moons (what is with this lame terminology anyway?) will ping ZeroTier by default.
From what I can tell ZeroTier seems nice as long as you're okay with using ZeroTier's servers for things (a curious trend I've noticed - so called decentralised services will always be great until you want to have fully independent servers). Sure, you can find github issues telling it's possible to set up your own planets, but the software seems somewhat complex and there's no documentation for it, and moons (what is with this lame terminology anyway?) will ping ZeroTier by default.