Like I said on that thread, skip the AD700 if you want bass.
Might I suggest the HD598? It's mid rich, very clear, and musical. It has plenty of soundstage, a complete beast in positional cues for gaming, and does music well, if you're into a mid and treble centric sound. The bass isn't lacking, but it isn't prominent either. I'd consider it a baby K70x without it being so anal about amping, though the E7/E9 definitely helps it quite a bit.
I just want to find a killer gaming solution and will compliment rock type music. The dt990's were impressive for gaming, but I don't know what to compare it to since i never tried anything in its class. Do you know what i'm saying? I'm not too worried about the bass presence, the ath m50 and dt 990 offers me the best of both worlds with the closed tight prespective(m50) and then the airy open feeling with the dt 990. I jut might have to give it time with my dt 990's tho everything is still very new just revieved the fiio combo and dt 990's last week. Are the hd 598's open or closed? And how was the band? i heard senn's have cracking issues