I made some measurements on #OpenBSD regarding web browsing with Firefox and Hyperthreading, since web browsing is a main (if not major) activity on a computer nowadays.
1. If the CPU supports Hyperthreading and you switch it on (hw.smt=1), pages do load approx. 20% faster than with hw.smt switched off (0).
2. Same pages do load approx. 50% faster in Firefox/Linux than in OpenBSD (under similar conditions).
I didn't make a big survey, but could confirm the results on 3 different computers.
@Haydar OpenBSD just isn't that good of a desktop OS IMHO. But so many people try to force it to be one. OpenBSD for servers is a great choice. As you already said: secure, excellent docs, and sane defaults. If you don't want to run the fancy new stuff OpenBSD is an great choice.
One of the first Mastodon instances, there is no specific topic we're into, just enjoy your time!