So what about VR and gaming? Is the positional 3D audio here actually worthwhile? For me the application of VR is the reason I am looking at these but doesn't built in 3D audio from the headset and the head tracking from the headset's sensors defeat the purpose of a second head tracker in the OSSIC?
Besides the Sennheiser GSX 1000 has a binaural rendering engine that does 7.1 surround pretty well from what I heard even with stereo cans for ~$200 so again can you really justify a single set of these cans when most of my headphones will work with the Sennheiser for gaming.
I've never experienced VR gaming but I follow developments in the game industry pretty closely and personally I feel that Ossic is unlikely to be much of an upgrade for games. As you point out, the game already knows exactly where your head is, and your eyes are reinforcing that very strongly. With good headphones, you should already be 95% of the way there, so the questions is whether the Ossic X is good enough to get you another percentage or two towards perfection ... or whether (as I rather fear) it backs you up a couple of per cent by being sonically inferior to the sort of headphones than a Head-Fier would already own. Also, you're puttiing what look to be some pretty heavy cans on a head that is already wearing a VR headset. If I were buying for VR I'd go for some decent IEMs.
In my envisaged use, I'll be wearing the Ossic for ordinary PC gaming ... makes a lot more sense to me because that's where the added immersion gains you the most ground.