Having spending a few days with them, i have mixed feelings about them....
My benchmark is the RE 400, and compared to them (yes, i know the M6 Pro are a different sound signature), yes they're good, specially for the price point, but they're definitely not a game changer, the mids are recessed, maybe with some burn in they will become more prominent, the detail it's also not on par (although for the price it's not bad at all), and the fitting, i can't believe how hard is the first time putting them and getting a right fit.
Having said that, the M6 Pro have a better build quality, the bass is enhanced but it doesn't get boomy, it's very tight, the highs are crisp, some sibilance is present on certain tracks, and with some badly recorded tracks, they get quite painful. They have average soundstage, but have a lot of "air between instruments.
In short, for their sound signature, they're great, have a tight and enhanced bass, crisp highs, recessed mids (i hope they get more prominent with some burn in), and you couldn't ask something better for the price.
Do they get better mids after the burn in? Thanks guys