[TheFlyingFish]

I've tried both. I ended up going with Tailscale because:

- Better throughput overall.

- better NAT holepunching. E.g. ZeroTier gives up entirely with "symmetric NAT" where each outbound connection gets a random source port, but Tailscale has a few extra tricks that it can try (including opening a whole bunch of outbound connections, trying ports at random, and hoping the birthday paradox will kick in, which I think is pretty cool.)

- But most of all, Tailscale didn't suffer from weird intermittent throughput/latency issues between different cloud providers the way that ZeroTier did. Sometimes my machines could talk to each other pretty fast, other times it was clamped down to ~10 MB/s for no apparent reason. Sometimes it only showed up in one direction, sometimes both. I gave up on trying to troubleshoot it when I discovered Tailscale.

That said, I still like ZeroTier a lot and think it's a great project. It also provides a whole LAN layer, with stuff like actual broadcast traffic, for which Tailscale has no equivalent.