I adore openbsd and have been using it since 4.x however it is still slow, not slow to boot or anything like that but if you run it as a web server it manages about half the req/s of Debian. Network performance is also slower than Debian if you're using it as a firewall (but I still prefer it as the syntax of PF is just perfect).
there's a lot of optimisations they don't engage with because it makes the code "ugly" but there's a larger one here, where they disable hyperthreading outright due to side-channel attacks.
It used to be faster than Linux for that, but that's been a while ago.
I moved some stuff away from OpenBSD when the release of Linux 2.4 implemented all missing firewall functionality - but kept others still due to the early issues with the 2.4 kernel. But by the time 2.5 was getting decent - roughly a year before the 2.6 release - in most cases just using Linux with a custom 2.5 kernel was the better option.
