I just switched to Octane 3.0 and it went off without a hitch. The new interface takes a little getting used to and finding some thing was a fun experience. I do like a few of the new features including the ability to save render states. Octane now does some animation rendering, if they did it before I never knew. I'm not much into animation at the moment...
My work flow seems a bit smoother now with 3, it ficed a couople of annoying bugs I had with 2. It's well worth the update if your on 2. Right now it's only $49 upgrade for the standalone, plugins are additional $49 each.
I still have on my wish list for Octane is the ability to queue up renders to run automaticly. Would be nice to set up a few renders to finish and start new ones without my being there. Hell if Lux Render can do it for free so why can't Octane? Especially for the money it costs. Still Octane 3 has a thumbs up.