Mainly at home. I have several old Apple G4s i run NetBSD/macppc on. A few years back I wrote short guide on installing NetBSD on these machines. http://www.rabbitfarm.com/cgi-bin/blosxom/netbsd
Right now, 10.0 BETA on my spare T420 Laptop. I have 7.02 on an old AMD333 system and trying to get 9.3 on it. It is hard going because there what I believe a motherboard issue with the CDROM Drive. And SDF :)
I hope to use it on my main system, a W541 Thinkpad. It works, but the Nvidia GPU (it as duel GPU) heats up a lot. I am not sure how to even diagnose this, but as the BETA persists I will keep checking to see if the issue stops. The W541 does not allow one to disable Nvidia :(
AFAIK there's no support for Optimus graphics on *BSD unless either of the 2 can be kicked out through the BIOS. I'd give an attempt to disabling nouveau/nouveaufb on boot.