alt Hacker NewsTheir use of addressing by keys instead of by IPs seems to be the main differentiator. Also the support for custom transports (BLE, LoRa, Tor) which appears to be in progress and not yet fully implemented.
I love Tailscale, it's deployed on all my devices. But I might check this out for the transports part in particular.
Tailscale uses MagicDNS which allows one to auto-generate a semi-memorable private hostname as well. I'm in the networking industry so I'm not seeing anything truly groundbreaking or that isn't offered elsewhere.