Stunning 3-D digital imagery, delivered directly to your eyeballs: This is the future of computing, say Facebook and Microsoft, which are placing big bets on virtual reality to be the new way we’ll interact with technology. Rift—from Oculus VR, which Facebook bought last year for $2 billion—hits shelves the first quarter of 2016. Microsoft’s HoloLens could show up as early as this fall, though Microsoft has been vague about its release plans.

Both Rift and HoloLens are headsets that use tiny LCD screens and motion sensors to alter the reality around you. But their differences are as striking as the similarities. Rift shuts out the real world altogether, creating a computer-generated environment that can transport you anywhere from an alien planet to an urban cityscape. By contrast, HoloLens’s mixed reality overlays 3-D images on the real world, such as a “hologram” of a tiny building that appears to be sitting on a coffee table that’s really in front of you.

Like practically everybody who has had the opportunity to test-drive Rift, I knew it had the potential to be transformative within seconds of strapping it on for the first time. When I stared down a dinosaur that was roaring in my face, my brain forgot that it was processing computer graphics in a way that was new. Standing on a skyscraper’s ledge, peering down at the city below, gave me vertigo.

Trying HoloLens is also fun and fascinating. But more than Rift, the experience feels like a work in progress. The version I used at a Microsoft conference in April 2015 was actually less impressive than an earlier prototype, because the “holograms” were visible only when they were smack in the middle of my field of view–a technical limitation that Microsoft’s splashy HoloLens videos don’t convey.

It’s only natural that Rift feels more fully baked. The gizmo first attracted attention back in August 2012, when Oculus raised almost $2.5 million in a Kickstarter campaign. It began shipping developer-kit headsets to backers the following March, and has revealed multiple upgrades to its system since then, each a bit more dazzling than the last. Those who are curious enough about the technology to experiment with an early version can buy the Oculus Developer Kit 2 edition right now for $350. Oculus hasn’t yet announced the price for next year’s consumer version, but says that $1,500 will cover the cost of both the headset and the powerful PC it requires.