modded HD558 vs ATH-700x vs ATH-900x

[MalcolmSex]

I am looking for a set of open headphones to use 50/50 for gaming (and general pc use) and for music (and as ear muffs) in my walk to class. I listen to primarily alternative rock, but also a little bit of rap

As I see it, my options are
Audio Technica

-ATH-500x $80

-ATH-700x $120

_ATH-900x $145

Sennheiser

-HD 518 $80

-HD 558 $125

-HD 598 $140 (through craigslist)

 

Any of these are theoretically doable price wise, but saving money is never a bad thing. I'd probably use it to go skiing.

 

I am leaning towards any of the Audio Technicas as they're stylish (which is a plus for me), and I have heard good things about their soundstage and comfort albeit at the cost of weak sauce bass. I have also heard that removing a strip of foam in the housing of the HD 558s makes them sound more comparable to the HD 598s [http://www.headfonia.com/sennheisers-new-hd558-and-hd598/3/]. As for the 598s themselves, it just seems weird to pay more for those horrible colors, but maybe you guys can convince me otherwise. 

I am posting here so I can here what you guys think,