Without a doubt, castAR will close the kickstarter funding. So both of them are facing the chicken and egg problem, I believe castAR will have a huge problem here. To your "game changer" point, castAR is trying to reach a higher sky than Oculus.
I mean, I can see myself having a small space near my bed for Oculus and attaching it to the Steam Machine within a year or two. CastAR? Maybe 5 years ahead of its time? The current implementation of the magic wand worries me. From the video, the awkward looking Jenga-like game seems slow and not 1-to-1 interaction. Although it could be a "beta" thing, Oculus didn't have HD to begin with.
As gamer, I think HD Oculus would be a better purchase, and wait for castAR v2 or v3, I have serious doubt they'll reach mass market.