well CV1 will sport 1440p screen. That is barely 33% better res. Not enough a jump. Way things are, you would need to double the res to mitigate screendoor effect and general "I can see each an every single RGB diode" effect.
I am very happy with DK2 outside the res thing, if they would make 4k display, then update will be in order, but not before that. (that is unless optics would be changed so it would utilize more than (3cm)^2 in the middle of the screen :/)
AFAIK the pixel density of 1440P is double that of 1080p
this is huge.
Everyone I spoke to who tried crescent bay (if only i was one of them) said that the resolution was HUGELY better over the DK2. Sure a 4k screen would be nice (not to play at, very few would have a capable pc for 4k vr) but imo that will come in CV2 which is probably going to be 2 years or so away.