I just finished a 2 hour continuous session of Half-Life 2 and I my mind is blown. I'd say it is the best gaming experience currently available. It reminds me of the first time I played Quake 1 with a 3DFX card. Just, wow. Intense, beautiful, and gratifying.
I've had my Rift for almost two months now, and for the first time it feels like more than a dev kit. It feels like a product and an experience. For me, totally worth $300. For those of you still waiting, it will be so worth the wait.
I had my IPD measured professionally today, I have HL2 all set up, and I am well VR acclimated. For me, avoiding nausea is all about how I use the right stick (using vr_viewaim_mode 0).
I forgot how amazing this game is. They got immersion mostly right the first time around so the transition to VR is fairly seamless (as long as you close your eyes during the loading screen!) The design of this game is pure genius.
Thanks you Valve. I would buy the VR of HL2 version again, once for each eye.
Higher resolution, positional tracking, and hand tracking would make this experience just breath-taking.