I don't have an Nvidia card, but I've already made a note to myself that when I get my next system, it needs to have Nvidia graphics, for a number of reasons. The fact that Octane is Nvidia-friendly just puts it over the top. I'll definitely be looking into that, thanks!

(also, your gallery rocks! The "Castle Mage" image... I'm guessing you used raytraced DoF? That's a real killer when it comes to render times! It gets good results though. Usually I'm too lazy for that and I just cheat and do DoF in post)