TrackIR has been around for a decade now, AND you wont get motion sickness + you can see your keyboard/drink - so IDK why OR is getting so much hype since TrackIR seems more practical.
I agree. While OR might well be more immersive, there are certain things to take into account. Let's say for a minute that you're playing with OR in a Battle of Britain simulator - you're going to actually have to physically look right behind, to the left/right or above you, which might get a bit tiring. With Track IR, sure it doesn't fully immerse you but neither will it give you a stiff neck.