Tracked IR is great, it works and is really quite intuitive.
The Occulus (dk1 and dk2) are both dev devices, they appear low resolution (compared to standard monitors), have serious colour aberration issues and significant latency. The image quality is thus way behind a decent monitor. The latency is the primary reason behind sickness, which effects a significant percentage of users.
There are new devices coming to market within the next 12 months Razer, HTC/Steam, Sony, Occulus all improve on the dk1 and 2 experience.
I've used several and the newer ones are much better, although there is still work to be done, especially in the supporting software.
Unless the engine really supports HMD, the overall 3D experience is not good. I've used an Occulus on VBS3 and it was very poor. It was not the fault of VBS3 rather the 3rd party drivers used to "persuade" the engine to produce a stereo image.
There is also another interesting piece of tech that might replace TrackIR, and that's eye tracking. It's supported in this weeks assassin's creed launch. The technology is similar in price to the Tracked IR. It tracks where you are looking. It is currently being integrated into laptops.
http://www.tobii.com/en/tech/