You could have a steady head option that draws a red circle around your head at setup and make a swing w/o the ball to see how good you're keeping it steady.
It's basically a golf video selfie!
They have those. It's a video feed looped to a small TV (or iPad) near the ball.
A friend of mine uses Skype to video chat with himself. His one iPhone "films" him from whatever angle he wants, then his iPad is near his ball so he can see what he's doing.
It's a pretty great way to practice, eh @cedrictheo ? :)
I think it would be more distracting than anything. What's better than keeping your eyes down toward the ball? With GG, you could look anywhere, and you have to constantly change focal distance.
It's still $1800. I figure it might come down a bit, but not super cheap.
Good idea, though.
There are a few sports applications that some people are looking into. "Fitness APP"
Check out "Golfsight" with swingbyte.