I would definitely not say that VR helmet is better then full blown projection... far from it. Lets be honest here, the only good thing VR has is much lower price and space it requires ;)
VR is alright, if you are just using HOTAS, with no peripherials, even using mouse to press buttons in game is not that good because your perception of where you are clicking in game (distances etc) are not the same as what you will be doing with your hands (to have to keep reaching the mouse)
I can see lot of people getting the CV of the rift (probably me included) then when novelty wears off, and we actually have to fight and press buttons in cockpits etc... we'll start to get anoyed with it and then start to see the downsides... right now we can't see it, but I am suspecting this is how it will be few months/years down the road when/if Oculus becomes widespread and catches on in flight sim community.