Hey MLE, would you suggest the HD598 or MA900 sound-wise?

I've narrowed my choices down to the MA900 and the HD598. Which do you guys recommend?

Would an Astro Mixamp 5.8 do a decent job of driving either the HD598 or HD558s? Also, my budget is around $200 or so, so if anyone has any more suggestions for headphones in that price range, please list them!

Has anyone tried both the HD558 and the HD598 for gaming? If so, could you comment on their differences and if they're minor or large? Is the difference worth ~$60 more?

I've been using my ATH-AD700X for gaming the last few months, but the cable appears to be broken in one area. I'd really rather prefer to just buy a new headphone rather than to pay someone to repair it (I don't trust myself), and I've been looking at either another pair of the AD700X's or the...