Just an update regarding my new V2.0: The yaw problems I encountered during my first outing (detailed above) were only experienced once, and in passing (just after launch), during my subsequent two outings. In some ways, an intermittent problem is almost worse than a consistent problem. I will continue trialling.
I haven't attempted any long-range flights as yet, but my impressions of the V2's Ocusync are very positive. It's noticeably better than Lightbridge. At the margins of connection - typically with trees and other objects between the controller and the drone, the signal is stronger and the live view is more consistent. It's by no means revolutionary... but it is a marked improvement.
I like that the drone will automatically switch between 2.4 GHZ and 5.8 GHZ to get the best signal. It's easier than having to do it manually mid-flight. And sometimes you just forget that your bad connection is due to interference on the 2.4 GHZ band, and don't think to switch over.