By comparison, I've tried both DK1 and 2, and people online all said the DK2 was a massive improvement and that you could hardly notice the screen door effect... It was the only thing I could see, completely unusable. They are saying the same about the CV1 but I cant see how going from 1080p to 1200p is going to make a big difference if going from 720 to 1080 didnt.
Whilst there are a few people who seem positively evangelical about VR, it needs much more than that to become successful.
It will be interesting to see what this "major breakthrough" HTC have made, but if it isn't at least a 1440p screen then I can see me skipping the first gen (or buying and almost instantly reselling as happened with the last two).