ethanwethinOnce I am able to get the 6XX I can formulate that opinion
But by design alone I can probably derive that 6XX will be better for positioning and immersion due to their super open design (not a bad thing. It might freak out if they aren't prepared for How in home the sounds might feel. Going of off playing once with HD558s)
ethanwethinThey both have different kinds of bass but typically for gaming you'll be wanting to hear the positioning of your enemies so a clearer soundstage is more important, which makes the K7xx a no brainer.