As someone who develops VR on a daily basis, I'm skeptical that 3D over 2D is the key. When I first tried on a headset, and watched a video from up high, my fear of heights kicked in. Now I'm almost completely immune to that effect, but I still routinely do things like try to set a tool down on a virtual table. I suspect VR will be good for hands-on training (where it's more about the sequence than the "feel" of it) and psychological training (how to deal with an angry customer), but maybe the psychological benefit wears off like my body's reaction to being up high in VR.
Have you tried to test your fear of height in real conditions recently? I'm wondering if the desensitization you experienced in VR have effects in real life.
I just went on a zip line for the first time, and climbing their tallest ladder was pretty unnerving. I don't have a great fear to begin with, but my the wow-I'm-really-hear effect has definitely gone down. Maybe if I had done that exact zip line in VR, it would have helped? I do believe VR can help with phobias and PTSD (http://www.virtuallybetter.com/), but I wonder if its benefit goes down with exposure (complete speculation!).
