In a teaser by TechRadar about Valve's upcoming virtual reality headset reveal at GDC, they cite a very interesting rumor from one of their own sources.
Furthermore, our own sources have told us that the headset is out in the wild and being tested by developers. One person familiar with Valve's plans told us that the headset in its current state is technologically "superior" to the latest iteration of Oculus Rift, Crescent Bay.

They don't really expand on what it means by "superior" however. All that's known right now is that Valve will be showing off their VR headset at GDC alongside the final iteration of their Steam Controller and new Steam Machines.