OpenBSD is made for developers by developers. Everything from configuration files in /etc to any system API calls are well documented in the man pages. They treat the man pages just as any other piece of the operating system. I.e. incorrect information in a man page is treated as a bug and dealt with just as diligently.

http://www.openbsd.org/cgi-bin/man.cgi

I moved from using Gentoo for 10 years to OpenBSD and have not looked back.

Edit; You gain quite a bit of time moving from Gentoo to OpenBSD because there is no requirement to compile or fix your operating system.