I'm looking for a pair of full size / on ear headphones that have a darker and more laid back tonality, something similar to the Earsonics SM3. I listen to one of everything, jazz, hip-hop, classical, electronic, etc. A good all-rounder would be nice. So far The ESW9A seems to fit the bill, anybody who owns it give me some more info about it or even compare it to the SM3? The HD600 interests me too, but is the bass thin with electronic and can it handle bass boost with an equalizer? 
 
My sources: Rolls RA53b (Not sure it can handle the HD 600) + Galaxy Nexus phone
 
Other headphones I liked/didn't: I owned the HE-400, returned it because the treble was too bright and the bass was lacking. I also sold the HD 598, loved the sound-stage but the treble was a tad bit bright for me and the bass response was OK for me but I was looking for a bit more when I listened to trap, rap, and dubstep. The SM3 had perfect bass amount in my opinion, a really nice midrange, and laid back treble (loved it) Only thing it was missing was the larger soundstage of my other opened backed headphones. 
 
Budget: About $350 max, would be willing to buy used/refurbished, but can't buy from forums like here. Thank you to anyone who helps and reads this, I appreciate it.

Low Cost:
Philips Cityscape Downtown ( on-ear, semi-sealed )
I really like the bass and the very neutral midrange.  The treble is rolled off a tad bit too much for analytic listening, but for fun they are great.
 
Medium Cost:
Sennheiser HD 449
I have not heard these, but please check out the reviews:
http://www.headphone.com/headphones/sennheiser-hd-449.php
The frequency response charts show a forward tilt which is what you are looking for.
 
Higher Cost:
AKG K550 ( around ear, closed )
These are my headphone of choice when the Denon AH-D2000 is not around.