I've used the Oculus Rift a few times, a few friends have the developer kit. The only thing to be careful of is giving yourself terrible motion sickness.
One thing that is lacking at the minute is the resolution, you'll notice the pixels at the moment, as you've only got something like 640x480 per eye at 720p. The retail version is hopefully going to rectify that. But the fact you can turn your head and get full 360 degree 3D is awesome.