Just picked these up yesterday and have been listening to them for about 8 hours (cumulative). So far, very impressed. To me they sound very much like the M50x (based on memory and "emotive impressions"). Unfortunately, I don't have a wired M50x on hand to A/B. Over AAC, the BASS is textured and extends throughout the frequency range. It doesn't overpower the mix, nor does it shy away. It's very distinct in its presence with no appreciable bleed. As anticipated, the MID range is absolutely fantastic. Both male and female vocals are distinct & detailed, with nuanced inflections easily reproduced. Acoustic Guitar on these is like ear porn. TREBLE is never piercing or overly bright, rather, it's very open & airy. Transparency and Instrument separation is fantastic, effortlessly isolating each instrument and it's respective character. For a closed back, the soundstage is much better than I was anticipating. Comfort is about the same as the M50x, which is average. I can use these for hours with no issues. The MIC is average. My voice, volume-wise, is good, and while still intelligible, it's a bit on the muffled side. It's competent enough for general phone calls, but it might not be the best choice for business calls. So far, I'm really enjoying these. If you're looking for pure sound quality, wirelessly, the M50xBT can't be beat, especially at $199 (worth every penny).