Just ordered one of these for a mini ITX build just for using Unity. Shame I can't find a decent budget motherboard from the current B250/H270 options but I don't want the hassle of getting an older one and it potentially not working.
The older ones definitely won't work out of the box. You can, however, send them off to the manufacturer to update the bios or if you have a Skylake cpu, do it yourself.