Another update:
The z axis isn't the only thing that doesn't work. It looks like positional tracking is only partially functional until you center the Head Mounted Display (HMD). I couldn't adjust driver height, some y axis stuff, and it became annoying. The fix was easy enough; I mapped a steering wheel button to the "Center HMD" function and I hit the button when I get in the car. I do it all the time in RFactor because the view has a tendency to drift sometimes, but never really had to do it in iRacing. After I center the HMD, positional tracking works correctly. Maybe it needs a baseline for the head position before it can work correctly, but you'd think that with the external camera it would be able to tell where my head is. I'm still messing with some of the settings in the app.ini file to get my head motion relative to the car and track correct, but for now have defaulted to the settings that are least likely to induce motion sickness.
The built-in headphones, which I found to be annoying, are very easy to remove. Twist a couple of plastic screws and they pop off. They use pogo pins for connectivity, so there's nothing to unplug and the screws are captive, so there are no tiny parts to lose.
Because the FOV isn't fixed, in-car black box displays (lap timer, tire pressures, etc) are in a really bad place. Those can be moved in screen edit mode, so I re-sized them and dragged them to where I can see them without looking down and to the side.
This thing sucks for glasses. It's easier to put on with glasses, but I'm wearing relatively small glasses and they do hit the lenses. It's nowhere near as bad as the DK2 was (I had to buy new lenses for my glasses after using them with the DK2), but the new rift lenses are also plastic, probably for weight reduction, so they scratch easily and mine already have a few fine scratches. I found this place that makes prescription inserts for the rift and ordered a set. I'll update when they get in:
https://vr-lens-lab.com/There's also a company that makes a spacer insert for glasses wearers, but it reduces your FOV, is still a Kickstarter, and the product pictures look like it came off of a 3D printer, so I'm guessing they are still in the prototype phase.
That's mostly it. I don't think that VR is a mainstream technology yet, but with this and the HTC Vive, I think that we just got a lot closer.
If anyone wants to give it a try, then feel free to stop by the shop and take it for a spin. I've got VIR loaded up, and with this rig, I can even fit Rodney in a Miata.