[tyfon]

I have OpenBSD on my firewall, a small old machine running irssi and an old laptop for fiddling.

My experience is that it's simple to use and well documented.

[keithpeter]

I'd concur with the simple to use and excellent documentation. I use OpenBSD on an old laptop, see...

http://sohcahtoa.org.uk/openbsd.html

...for details. And I'll be updating the page for 6.2 in a bit.