HMD relative / facegun are something I'm ambivalent at best to, you instinctively "know" where your chest is relative to your head, so you know that if your lookng left with your head, moving the thumbstick forward will create the illusion of moving to the right. I'd prefer VR headlook to work like it does for a CMDR on screen with a trackIR, where the direction of the torso is the direction of travel, and the headlook is relative to, rather than authoritave over, the direction of travel. However, the beauty of all these control scheme options is they are relatively easy to code in options to switch between them once you have the VR cam attached to the avatars neck.