Got these in yesterday and they sound pretty bad, imo. Really recessed on the high end. Also, there's a TON of noise while playing/for a few seconds after stopping play.
The connector is the same as for the M6 Pro, but it is not long enough to provide a secure connection to them, so not an option unless you remove some of the plastic from the connector housing on the cable. Overall, I'll get some use out of these on a desperation basis, especially if they loosen up a little on the high end, but the hopes of being able to make my M6 Pros wireless didn't come true.