Ordered my CV1 in the first 5 mins, but I finally got done trying the Vive and CV1 here are my thoughts as someone who owns DK1, DK2 & GearVR:
The CV1 was the best out of the two in terms of VR presence and experience, here are the reasons and what I noticed as differences -
1. Optics Quality: I got a chance to view both the Vive and CV1 lens, the CV1 has a superb sweet spot for aberration and distortion free viewing, there is no noticeable chromatic aberration like the DK2. Fellow DK2 owners who hate having to tighten your straps and carefully position the lenses w.r.t to your eyes to avoid a blurry mess will be pleased. I also played around with the physical IPD mechanism which is fan-fucking-tastic, feels high quality and long lasting and the position adjustment is detailed and stays where you leave it.
Another part of the optics that definitely helps is the non-circular shape. If you have the DK2, try looking at your nose or the left and right edges of your visual field when you have the headset on, you will notice that things quickly become blurry and colors seperate a LOT.
If you have also played FPS games like Fallout 4 and Battlefront using VorpX w/ the DK2, you will know that unless your eyes are pointing in the same direction of your head/face that clarity is quickly lost which makes tracking targets that come into view and move away from the center of your vision is hard to get used to because you have to move your entire head instead of naturally moving your line of sight in your field of view. The new lenses make this natural and seamless in a bigger area of your FOV.
Which brings me to the final point about the lenses, the FOV, oh god damn the FOV, its in that sweet spot. From the DK1 to DK2, the VFOV and HFOV were sacrificed and thus you got this "scuba mask" feeling which at least for me substantially reduced chances of achieving presence for a large continuous amount of time. From my demo, this scuba mask effect is greatly diminished to the point that your peripheral area of vision is sufficiently filled with pixels to give you better feeling of presence.
Palmer, you made a good decision splurging for these new lenses, at least for me.
Displays: The CV1 also had an advantage here when compared to the Vive IMO but a much smaller margin then the lens, the pixel fill density was noticeable better and the low persistence kept light from bleeding and blur from being a problem, the Vive also does this pretty well but there is more noticeable smearing in the Vive. The other big difference is the noticeability of SDE and pixels. DK2 owners know when playing something like Assetto Corsa, if you focus really hard on an upcoming turn, you often times get pulled out of the immersion because your brain actually notices that what you are seeing is just pixels that are changing color, rather than a cohesive image in a wide field of view. This effect is significantly diminished w/ CV1's screen as compared to the Vive, in EVE Valkyrie, even when I focused on a ship to lock on, I never fully lost immersion with the "oh this is just a shit heap of aliased pixels I'm looking at" feeling. Because of this, large scale objects in the background also feel more "3D", the planet I was fighting above in EVE actually felt like a massive body under me as I flew around dog fighting.
Weight: The CV1 was margially more comfortable than the Vive, but the most annoying thing was still the cable and how it sometimes pulled on your face when walking around in both the Vive and CV1 (the CV1 was more standing so I noticed the cable less and stepped on it less often).
Motion Controls: The Vive does a little bit better here when it works, I found the Vive controllers to be more comfortable and natural to hold than the CV1 Touch, both the Touch Vive sometimes would skip or reset a bit when enough of the controller for a hand was ocluded (when hugging your hands to your chest and hunching for example), but when it worked the Vive and Touch were solidly 1:1 with a slight edge going to the Vive.
Audio: CV1 is a clear winner in this regard, I am a bit of an audiophile and have 10+ different headphones including a Bang & Olufsen set, the CV1 was comparable to most high end audiophile headphones I own in terms of sound stage and balance of sound. The usefulness of the uniformity of the CV1 headset's cans were apparent, directionality and "positioning" of sound in the CV1 demo was noticeably better than the Vive, which felt like the crude circular directionality and distance drop off in magnitude that we are used to in regular games. In the CV1, 360 degree spherical directionality and much better distance differentiation was possible.
Conclusion: All in all, in addition to my $2k PC and $5k gaming chair setup, the extra $200 for the CV1 made sense, I am very happy with my future purchase based on my demo experiences.
