For me, VR is comprised of three separate components: 3d, 1:1 tracking, and field of view.
I had tried 3d back in the early 2000's with Aces High 1 thanks to a set of shutter glasses gifted to me. The 3d looked amazing, especially when landing. I could actually judge how close I was to the ground. But it came at a price: half the FPS since it had to paint two different screens for left and right eye and display them alternately. Additionally, the gunsight was focused at the physical distance of the sight glass, so I would see two images when trying to look at a target in the distance. Despite the immersion of 3d, I quickly and easily decided that it wasn't for me. At the time, I had a 1600x1200 monitor with 85Hz refresh. Aces High 1 would run locked at that with vsync. It was beautiful.
The jump from a pov hat to TrackIR is a big one. It takes a week or two to adapt to TrackIR, but the ability to use head movement to look around and free the POV hat for other functions such as trim controls typically found on fighter jets was worth the cost in money, cpu performance, and view stability. I think I actually had better situational awareness with the POV hat: I knew exactly which direction I was looking and the view was rock solid stable. But with a good TrackIR profile, the gunsight view is stable and I can generally keep track of which direction I am looking. But with amplified head movement driving the view direction, it is hard to "padlock" a target smoothly and still be able to easily go from a forward view to an aft view within the angular limits of the monitor and TrackIR.
The Rift really shines in 1:1 tracking of the view. If someone made a device identical to the rift, but with a single 2D screen at 4K resolution, that would be my preference. Forget the 3D until the resolution/gpu power catches up. Give me 1:1 tracking with 4K resolution in 2D. Also, unlike the TrackIR, I don't have to constantly keep re-calibrating the Rift. Once I am flying, it always seems to track my head correctly.
The field of view is something I don't see mentioned much, but is a huge gain. Most people were using three monitors in a horizontal configuration to have a very wide field of view. But in air combat, the vertical field of view is far more important. When I am flying with the Rift, I can see forward and even up quite a bit to track a bandit and still glance down at the gauges with my eyes. With TrackIR, I have to move my head up to follow the target then move my head down to glance at the gauges and hope when I move my head back up that the target is still where I expect him to be. When you fly a helicopter, such as the UH-1H in DCS World, you can easily see where you are going, the panel, and even the view out of the glass at your feet. This allows you to feel the relative motion of the helicopter much better, allowing much more precise control of the helo with very minor corrections on the cyclic stick. It is in the realm of helicopter flight that I am most conflicted with VR vs 2d/TrackIR. It is easy for me to pick 2D/high resolution for dogfighting in fixed wing aircraft, but VR improves the helo experience so much that I think I just might give up the resolution, especially if I am not flying combat missions.
I have been waiting for years for VR to become both affordable and high enough in quality. It is so close. But I think it is still 3 to 10 years from being good enough for me. I have been waiting nearly 20. If you have $400 to spare, the Rift is worth every penny just to preview the state-of-the-art. In Aces High 3, I think VR is 100% acceptable for air-to-air. But in DCS World, I need the resolution more than I need the 3d/1:1 tracking/FOV... except for helicopters.
