The thing with the white (or green!) K-turn is that while it's very powerful and nice to immediately get behind someone, it's also good for recovering from a bailout move (usually a 3 turn or 3 bank to avoid blocks and/or shots). The Countess excels, here, too, because she can take a 2K after a "swarm avoidance maneuver" and both keep her guns close and stay nearby where it's easier to dodge arcs. Interestingly, by staying close to opposing ships, it keeps the K-turn open, whereas a regular Defender may have to deal with extra chances to get blocked and/or shot by ships with actions. More K-turning options = more turns where you don't get shot by unstressed ships.
As an aside, I want to thank everyone again for all the kind words that have been said. The original post has hit 100 likes, which has pleased me more than it probably should.