Here is what is happening, and what I interpret from what HTC said regarding this before.
With VR in flight sims now, it's very, very difficult to look behind you, even looking 90 degrees to the side requires a radical head/body movement. It's far, far slower than TrackIR or thumbhat/numpad, to the point that VR play would be at a massive disadvantage.
So, what HT is trying to implement (again, all my interpretation, not his per se or necessarily accurate/correct), is that the same VR view you get looking straight ahead, can be added to each of the various hat views. IE if you push thumb left/look left, you'll get the same view as anyone NOT in VR is getting, but the scene will be IN virtual reality, and you can look around a bit just as you do while looking forward. What I suspect is HT is just deciding/tinkering on just how much, if any, looking about one can do while in VR and in a non-frontal view.
It isn't disorienting at all, not for me in the slightest, it's just like having a VR unit going, and being able to look around as you did at your monitor in terms of the thumbhat/numpad and lcd interface when using the various look directions. The view isn't "accelerated" as it is in TrackIR, it's just "combined", if you so choose to use them, with the thumbhat/numpad view system. You don't see the view quickly flip by to "look left" if you move your thumb left, as it happens in TrackIR, if you have "instant view" set, it'll instantly flick to the 90/rear/etc view you select with your hat, but just be in VR mode still. It's fast, and not disorienting nor does it affect immersion at all, at least for me.
In terms of the "landscape" moving faster than my head, no, it's not really like that, I'm referring to the scaling. If you use TrackIR, you'll know that you can scale just how much your head movement corresponds to the screen movement, ie make less head movement = far more in game/screen turning than reality, so that just a look to say your 11 o oclock in your seat = looking right behind you. What HTC has started to do with this new VR view implementation IMO is just to add that type of advantage to VR gaming as well. IE instead of being locked into 1/1 movement, instead of scaling the head movement in VR, which would be difficult or maybe even not possible, I'm not sure, is to give the VR player the ability to combine the hat view system with VR, a sort of combination of both methods, sort of like putting VR into the hat system I guess.
I guess bottom line is this: move hat to get VR viewpoint in corresponding hat direction immediately, while still holding head forward and not having to crank your entire body/head around to see beside or behind yourself. IMO it's the best compromise/combination we can get, and as I said, I know other sims with online servers are screaming for this type of idea, as you are at a massive disadvantage in fights with standard VR vs TrackIR/thumbhat. I wish I could demonstrate just how badly in person, if i stuck either VR unit on anyone, and then fought them with just trackIR/hat, prior to what HTC has started to try and do, you would not be able to keep me in sight worth poo, and would die very, very quickly, regardless of how good you are outside of VR. It just takes far too long and is too uncomfortable and slow to try and keep a target in your forward view while in VR the standard way. Now, once this new way is fine tuned a bit, IMO it'll be nearly an equal playing field.
It's very important too, as VR is going to be a big future in all games including this one, yet if VR players were to be at a big disadvantage in fights, it would be a large negative to have to combat, and would create complaint threads beyond anything yet seen, especially once VR costs come down and it becomes mainstream, which is only 2 or 3 years away IMO. HTC is well ahead of this issue, it's impressing that they've ID'd this as a future potential big problem, and I think their solution is by far the best option, and once it's matured and been tinkered/tuned/etc, will at worst not be an issue to keep people out of VR and potentially the game itself, and at best be the standard for the entire online/pvp flight sim genre.
edit - I'll try and make a video of this to show instead of tell, again, this is a critical feature/issue for VR and future VR players, which will be many, it's inevitable.