Rust is awesome. It's likely a better fit than Go for applications like this, as it has more predictable performance[1], and more control over the scheduler (as you have to roll one yourself).

I attempted an implementation of Tor in Rust, but because I implemented it in Go a few weeks before that I got bored quickly. That said, some ideas I had for the Rust version have made it to Tor itself (or soon will), such as my ideas on transparently load-balancing Tor hidden services: https://gitweb.torproject.org/torspec.git/tree/proposals/255...

[1] note that in the land of Tor, unpredictable performance (for example because of GC pauses) could lead to user deanonymization.