Let me start by just saying what I like about these.
Sound Quality is decent/serviceable. I'm coming from comparing these to a pair of M50x's and they hold up decently. However, when Noise-Cancellation is turned off the bass is very muddy and muffled sounding. Way too heavy in that dept. Turning on the Noise Cancellation helps to reduce this mildly. My pair made strange noises at random in the left ear that were fairly loud. They're a little small on my head and fairly heavy to wear.