There are some good compromises with good noise canceling and good sound quality, but none of them has the sound quality of DT 990 or Bose's quietness.

I also had to replace the first set I received due to a weird static noise in the left ear that was constantly there

It's a loud mechanical popping noise, like the hinges are

Not much noise isolation - Even when they're blasting, you can still hear what's going on around you

A bargain, and they isolate outside noises better than i expected but they get loud enough to hear from 50 feet (no exaggeration)

Even pristing audiophile recordings with excellent vocals begin to get that cheap pop-music sparkly feel to them due to exaggerated "s" and "sh" sounds