I've run my single Khorne Drone in a dozen or so games now, and found it to be a pretty pleasant little airsupport beastie.
I've never had a problem with it's low
BS, the blast, template, and twin linking all help to make it a pretty average shooter. Situationally, its very versatile, being able to sling blasts across the table, or lay down close support template fire for your assault elements. The jink is really very good, but doesnt feel broken as they only have two hullpoints. If enough fire is dedicated at them, they will go down to the few lucky hits that get through.
Be careful when hovering that you are plenty far enough away from enemy units. They might have a 2+ save, but they'll die like nothing to any sort of assault.
Never used more than one, but a 2 or 3 would certainly put the hurt on.