Now that both the Vive and Rift are out and both systems have their own motion controls for full functionality, they end up looking very similar on paper. The Vive has the benefit of whole-room VR, though cable management is inconvenient if you're lurching blindly around a room.
Immersive experience; Includes motion controllers and external sensors for whole-room VR
Expensive; Tethered headset makes whole-room VR tricky