I've owned a DK2 and I was demonstrating the HTC Vive at the EGX this year (as others have mentioned).
I opted for Oculus. Why not a Vive?
Due to the amount of time I play Elite, especially on the DK2 I had already, VR was going to be a must-have. If I can spend £200 on headset or £150 on a joystick, £500 isn't a huge leap for an HMD I'll use for three hours a day.
The implementation of the Vive has sadly ruled it out for me as a viable option. Why? Because it requires two wall-mounted sensors that are roughly 6cm cubed, with bright-green always-on LEDs. Not something my wife would accept in any room in the house (especially not the bedroom where my PC resides) and since I don't have a dedicated VR room where I could bury the cables in the wall, it ain't gonna happen.
The biggest issues (for me) with the DK2 were heat, weight and resolution. With the big plastic front-section and large straps it was very hot to wear in the summer. Although not heavy, after an hour of wear your neck notices. The CV1 has a fabric-like shell instead of solid plastic and weighs a fraction of what the DK2 did; it has much thinner head straps and has the same video resolution as the HTC Vive (which I've tried using Elite) which eliminates visible pixels, so it ticks all the boxes.
The revised version of the Vive recently announced (with front-facing camera) has slightly smaller sensors than the prototype I used last year, so they can be tripod-mounted - but do you have 15 square feet around your PC to accommodate two tripods with associated cabling across the floor? I don't. It also doesn't look to be any lighter than the prototype, which was a similar weight to the DK2 as just as strappy (read hot to wear).
I suspect that the Vive is going make people blow coffee out their nose when they announce their price. They've said theirs will be "premium" HMD. They also made a (presumably costly) last-minute revision to the consumer version to include the front-facing camera and they plan to include motion controllers, so the whole package is going to cost a lot more. That's not a bad thing, but the people will look back and see the Oculus as the entry-level HMD option.
The PlayStation VR price leaked yesterday and it was $800 (ex VAT & shipping), so the later VR's are not going to be any cheaper for some time.
On the upside the current generation of top-end 28nm graphics cards are £400-500 and there aren't many to choose from, but both AMD and nVidia are set to release a range of 14nm video cards this year. Now while the top-end cards will probably cost over the £500 mark, the huge boost in performance these cards should offer means the mid-rage offerings (GTX 960 price equivalent) should outperform the likes of the current GTX 980s. So look forward to cheaper super-powerful graphics later this year.
So it boils down to preference & what you can afford. If you have lots of room and don't mind the big sensors and have a bigger budget, you can go for the Vive and benefit from the premium headset and the augmented reality options the new camera will offer. If your PC doesn't have it's own study or office or you want something portable plus a smaller budget, you'll probably want the Oculus.
