For those who are new to VR, either device is a good choice, both offering benefits better than the DK2. However, for those who have had the DK2 for any period of time and who are regular users of it, they will have a mind more inclined not to overlook some of the rough edges in a new VR HMD, specifically the Vive in this case.
No matter which device, we're all good for VR to be here and money flowing into the segment. It's a critical time for VR. Unfortunately, the revenue projections for VR hardware sales has been downgraded twice due to the logistical issues hampering the fulfillment process. Oculus really stepped on their collective pecker with their delays. The perceived expectation was that new orders would roll out the doors on March 28th and they'd have had an abundant supply to meet at least much of the demand. Add that to the preorder flop on their website, and they have a couple of stumbles on their hands.
I read somewhere that it would be 2019 before Gen2 VR hardware would come on. If it is 2019 when the next version comes, I'd expect Q3 before it would be available. I'd not expect wide fov and 0 SDE until Gen4 of VR at the soonest. We may be waiting another 7 years for that. Such is life...I don't miss the screens at all even with my DK2.
Tony sold his DK2. I'd not spend the money to replace it with another. At least get the new one no matter what. Unless you can get one for 50 quid, you have to spend at least 400 for a good used one. You're more than half way there to a CV1, so a bit more means better hardware and longevity.