I just tried it; the latency is much higher than the Oculus Rift but it's still enjoyable. The demo app mainly has you flying around various places on Earth, but this comes with an SDK for further development.

I watched some folks in my office put it together and there was a bit of confusion as to how it was supposed to assemble (also reflected in some comments here as well).

The three biggest annoyances of the setup are:

- Higher latency

- Uncomfortable on the face (cardboard edges rubbing against skin)

- Unable to really fine-tune the focus

With the exception of latency, the other problems might be solvable with some more crafting. In particular, it would be good to put some kind of soft rubber grommet around the edges and then use some sort of head strap so you didn't have to hold it all the time.

Verdict: not perfect and certainly not going to be a threat to real hardware, but it does give you enough sense of presence to experiment.