Denon AH-D2000 vs Sony MDR-7509HD

I've heard the Denons in person.  I must say, they are quite clear and very comfortable.  Some people seem to think the swivels for the cups seem frail, the sure look it, but don't quite feel it.  They do need a decent amp though. 

I don't think the MDR 7509s are bad, in fact, I think they are just the V6s with a fancier connector (correct me if I'm wrong). 

Have you tried either out yet in person?  I haven't had the fortune to find a pair of the MDR 7509s.\

Edit: Yes, they "need" an amp, at least it's recommended.  Sorry about that.  Here's one thread with a short discussion.

The D2000s are the best I've heard, but I've heard very little.  Much better than any Sony's I've tried (including the V6s).  Not so cheap though.

The D2000s are in another league.

As in they are far better headphones. Better all around, every single way. Only thing is, they aren't as portable.

You're not going to get a straight answer regarding the D2000s, they're bass-head headphone and so have a large following. If you want a comfortable, good looking, bass-dominant closed headphone then go ahead with the Denons, they don't need an amp what-so-ever and will work well directly from your mobile device.

People here are mistaking the 7509HD for the 7506, neither are bad headphones but the 7509HD have better extension than the cheaper 7506. I would consider them an excellent monitoring headphone, perhaps a bit boring for long-term music listening.

For techno people seem to prefer bass-forward headphones like the Denons, Ultrasones etc however I prefer a more balanced approach, you might want to articulate your sonic preference. Classical on the other needs to breath in the form of an open/semi-open headphone, they also need to be closer to neutral otherwise real instruments don't sound like they should. If you want a headphone to do everything quiet well then the closer to neutral the better.

Some neutral examples: (They would require an amp)

Beyerdynamic DT880

Sennheiser HD600

AKG K701

Getting a can that would do both classical and techno extraordinarily well at the same time will be hard.  The Denons will take whatever techno you throw at them and play it back with the type of authority that's more akin to a speaker setup rather than a headphone, but the soundstage it has isn't the biggest for classical.

The Denons do not need an amp, but they would like one.  They improve a decent deal with one, as many people have pointed out throughout their experiences with them.

Have you ever considered getting two headphones?