QUOTE (Eliteforce @ Sep 9 2009, 00:05)

tedgo, I'm listening mostly to metal (Opeth

) and rock and sometimes even some electronica.
Then indeed the HD600 would be a good choice for you.
I think the balanced mid-range (some say it would be too prominent) fits good to rock/metal. Especially since you prefer a flat sounded headphone.
They are flat sounded, but some say they would sound not as clear as Beyerdynamic or AKG (not my meaning. I think the HD600 are much more neutral than the too high AKG or the too "effective sounded" Beyerdynamic).
QUOTE (Eliteforce @ Sep 9 2009, 00:05)

I have considered the K601 but figured out, as you did, that the sound would be too neutral, i.e. bass shy. Some guys on the german hifi-forum said it sounded a bit like an old kitchen radio.

Depends on the equipment the AKG is plugged in.
They are very choosy.
On my old Onkyo DX-7711 cd player they sound very ugly, on a philips mini-hifi-system they sound very good and very silent, with nearly no bass, on pc.
QUOTE (Eliteforce @ Sep 9 2009, 00:05)

I've also considered the D1001, but its more or less closed architecture won't help with the muddiness, right? Besides, I think that the whole Dxxxx range is overpriced.
No, i don't think so. I heard the AH-D1001 on saturday in a hi-fi shop (my HD580 begins to get weakness of old age in between

) and was surprised about its clear sound. There are some closed headphones around with good sound. Not as "airy" as open architecture, but more "direct" and still clear.
Regarding the HD595:
I never owned them but tried them too on saturday.
They are a class below HD580/600/650.
Less clear and less bass but still good.
And still far better than your PX100

Compared them with the Denon AH-D1001 at the hifi shop and the HD595 lost the competition for me...
But maybe only caused by the loudness the Denon's gave to me compared with the sennheisers. And the test was very short (haven't had enough time...).
You should better test them by yourself. Its really a matter of taste.
And you'd save some money with one of this two headphones (in germany they're available at about €110, don't know about your location, though).
EDIT: Forget the HD555!