Which would you buy and why?  M-Audio Q40 for $120 or Ultrasone HFI-580 for $138.  How do these compare?  Thanks!

I've decided to take the plunge and get a decent set of headphones.  I wouldn't say I'm a bass head, but I do like my bass.  I like it loud, but accurate.  I also love clean mid-bass  (typically test with Natalie Merchant's Tigerlilly).  Finally, I hate harsh highs.  I primarily listen to rock...