So "People sometimes ask me to describe the differences between Nebula and Tailscale" and the answer is "performance and scale", but you don't have clear comparisons for those numbers?
Publishing repeatable benchmarks is hard, and when doing open source work, it just hasn't been a priority. As I replied above, if I'm going to say it I should prove it, and I promised to do just that.
And a counterpoint: tailscale does mention in the "Tailscale vs Nebula" article on their website that performance is just about the same but similarly provides no proof. This is motivation enough for me to show proof of the opposite, I guess.