As I said I have not tried them myself so I can´t really say. But the people that have tried them are game critics and they say it is a awesome feeling to play with them and that there is a feeling of being in the world, and they have tried it with Doom not the best game on the market right now so it can´t be that bad.
As for the resolution, the people that have developed this VR headset say that the are looking in to make it higher when they release the costumer version. And the MS is said to be near nothing, they show what the people see in the headset on a screen in some of the videos but always point out that there is higher MS on the screen than what there is in the headset.
As for the HUD and everything I cant say.
VR headset is not a new thing so I´m guessing with all the good critics this thing is getting it must be something good about it.
And if they are as good as the critics say it is, I would love to play Arma 3 with them.
The resolution is said from the dev team to be higher in the consumer version. And the MS is near to nothing, in a video I think I heard 0,7.
That´s why they have released the dev kit of Oculus rift so the game dev can play around and with it and see how the effectively can implement this to the games, to figure out ways to make it work with games and give feedback to the Oculus dev team so they can make it better before they release the consumer version.
About the feeling like playing in a mask I don´t know anything about cause I have´t tried them, but in the videos I have watched the critics say it´s awesome and it feels like being in the world so it can´t be that bad.
VR headsets have been around for some time now, so when the critics get this all worked up playing Doom with them there got to be something good about them.
If the headset is as good as they say, then playing Arma with them should be a really good experience.
Again about not finding the right keys on your keyboard, if you can´t play Arma without looking down at your keyboard all the time then maybe you should´t use this headset.