Just over 5 years ago I brought my second Virtual Reality Headset (at the time they were less than half their current price), an Emagin Z800. It featured dual OLED 800x600 displays and a built in 3 axis head tracker which could emulate trackir libraries to AH. It also supported stereoscopic 3D, which was extremely good.
Unfortunately a few months back after 5 years of abuse in AH, FSX, Arma, and a few other games my Z800 died.
Just before Xmas I acquired a shiney new headset - a Vuzix Wrap 1200VR. It features a pair of 852x480 LCD displays and a 6 axis head tracker. Though not quite the same quality as a Z800 it is ~ 1/3rd of the price. It also has some features such as SBS (Side By Side) Stereo 3D which gives much broad 3D support, and independent focus on each eyepiece (which I think is essential).
I've just started tweaking the 1200VR to work with AH, but first results are looking pretty good. Yes you lose a lot of resolution compared to a monitor, even more so if you run 3D (you end up sending 640x720 to each display, the headset likes the video to be 1280x720 SBS), but headtracking and stereo 3D adds a lot of immersion (also you use your head to look around rather than look around the screen). The cool thing about SBS 3D is fraps records it and it works with youtube-3D support.
The tracking only feeds in 3 axis's (pitch yaw roll) but I'm hoping vuzix will release some drivers in the near future to give full 6 DoF.
So though I'm still sorting out the headset setup to how I want it in between battles with the kid-ack and acting as the UN between the wife-ack and kid-ack I jumped into into the WW1 arena. WW1 style dogfights clearly show the coolness of a VR headset, stereo 3D and headtracking gives you a bucketload of fun. Unfortunately the rotary I use for zoom on my aging X45 is getting a bit wonky, so the bits where the zoom jumps around a bit is the aged X45.
Anyhoo, here's the results... a short fight in the WW1 arena in 3D (if you have a 3D monitor you can watch it on youtube in 3D).
http://www.youtube.com/watch?v=r0qvQQjdFjM