Yup that's them. The fucking scourge of the X universe. Devil
Have you noticed you can charge them up now? I'm liking them on my Truelight Seeker. A few of them doesn't seem to slow the game down.
There will never be a battle where six capships are in the same screen around a station, all firing at once.
Last night I had my first battle with a Xenon K (on a patrol mission), and it was firing on everything in the sector. I can't imagine seeing six of them at once unless the patrol missions spawn as many destroyers as they do corvettes.