whoa! i was reading up on that thread you linked and this really seems like it could be the one i'm looking for:
sennheiser hd600
i would have to save up a little more but it might be the perfect one i'm seeking.
this would be a nice step up from the a900x level, correct?
STRENGTHS
EXCELLENT TONE: I adore the tone of the HD600. The bass, mids and treble are beautifully integrated. The tone is very close to neutral, featuring a pinch of extra warmth and body.
MIDS: The HD600 has a slightly forward midrange that adds weight to vocals. There are no odd peaks or dips here. Simply put, the HD600 possesses a very natural midrange.
GENRE MASTER: The HD600 is ready to serve its listener. Whether you like pop, classical, rock, hip hop, r&b, jazz, funk, blues, country, electronic, dance, world, etc. it will be a worthy purchase for you.
TRANSPARENT: While the HD600 lacks the speed and agility of electrostatic headphones, and although the HD600 doesn't offer quite the depth of several top-flight dynamic headphones, the HD600 is still a highly transparent headphone.
BASS: Some people will ultimately prefer the bass response of the HD600 to its younger sibling, the HD650. The HD600 has a leaner, yet more neutral bass response when compared with the HD650. The two headphones are largely similar, but it is in the bass presentation as well as the lower-mids where the two Sennheiser models reveal their most obvious differences.
NOT TOO AMP PICKY: With a nominal impedance rating of 300 ohms, the HD600 really does benefit from amplification. However, I have found that this headphone is not particularly amp picky. It sounds fantastic When paired with most of the amps with which I've used it. Furthermore, it sounds particularly good when connected in balanced mode.
COMFORT: The oval-shaped earpads are made of generously plush velour material. This helps make the HD600 a very comfortable headphone to wear. I prefer an oval shape to a round shape because an oval is more form-fitted to the human ear. I have used the HD600 for several hours without break. I have not a single complaint with regard to its comfort-level.