Yeah, kits shipped in March. The hardware is incredibly polished for something that popped up on Kickstarter 7 months prior.
It's comfortable, tracking works wonderfully. The only downside is the relatively low resolution - which it's said will change significantly by the time a consumer version ships.
Still, I place it on a very short list of truly remarkable experiences involving technology.
The impact of the experience is hard to compare, this video [0] might give you an idea how convincing it is to put it on for first the time.
I'm very excited about what will come about as we move out of the stage of cool tech demos and existing games + head tracking to experiences fully conceived with the rift in mind.