I've used the Vector for 5-6 rides now. It appears to be working fine. I haven't run it side by side with my Quarq (my Garmin 500 is dead so I only have one head unit).
The power data appears consistent with perceived effort, and what I'd expect comparing it to past experience with a Quarq and PT's.
Recalibrating, and tightening the left pedal appears to have taken care of the descrepency in power balance I observed on the first ride.
After the initial set up, its easy to use, just pedal backwards a couple of revolutions to calibrate and you're good to go.
So at this point, my only gripe is the poor documentation for using them with other than a Garmin 800, and the lack ofknowledge by Garmin's support people. But again I guess that's to be expected in the initial roll out of a niche product.
Saturday's warmup ride before Six Gap:
http://www.trainingpeaks.com/av/CMHH...EEWFW7MGIRFS2E