It's awesome. Have been using it for a while. Ipv6 overlay network with e2e encryption. And it works well. Dns is blockchain based at the moment. It's neat. You can use it standalone or join the public one. There is also a mail system yggmail and a matrix chat implementation. All work as advertised.
Yggdrasil only does routing. DNS is not part of it. There are people running DNS severs on the network. And some of them are blockchain based, but that's not part of the Yggdrasil project.
I really appreciate that clarification. The "blockchain based" DNS server concept the parent mentioned almost caused me to bounce off of this project, which is otherwise very interesting to me.
Would recommend to try it