From my perspective, I feel the bass on the 990's is "perfect" to my ears. Yeah, it has the characteristics of a wild Kodo Beast(bad warcraft joke :P) and can get a bit thick and muffled on bad recording/bass heavy tracks,  but it's never over-emphasized in my opinion. Led Zeppelin has never sounded this awesome!. From the face melting mainstream guitar solos that will rock your socks, to the well balanced, low-end, soulful delicate sub bass sound spectrum of Classical Rock, the DT990's will never miss a beat as long as you stay true to your source.I remember going into discussions with driftingbunnies(another dt990 user who posts once in a while) he use to mention about the bass texture, quantity and quality of the Sennheiser HD650's. I recall him saying the Senn's had the quantity, but the beyer's had more refinement, better attack and a smoother rendering to it. I actually couldn't have said it better myself ! But i would love to try the 650 one day and do a full comparison of the two. 

The Wuss has the soundstage & misc areas covered, so I don't really feel the need to get into it too much + I could give my fingers a break ^_^  But let me tell you guys, the 990 scale extremely well with gaming and movies. The open airy atmosphere will leave you breathless; some days you might feel like hovering on water with all the much needed instrument seperation and crisp clean tracking. FPS games are a plus for these cans. If you play big hits like Modern Warfare 2 or Battlefield Bad Company 2, the indepth surround sound is phenomenal. The 880's might be more precise and have better accuracy, but gaming on the 990's is a dream come true. Throw in a decent tube amp in the mix and be astounded by the weight, body and circular bass motion that these headphone's will deliver. Truly immersive experience !