I have been using the xm3's for a year and a half, and reserved these on day 1. After eagerly awaiting the xm4's for the past year, sadly I really can't find any discernable difference in the noise cancelling quality. I was really hoping that Sony would offer something more than just a lateral move. If the ability to cancel noise is your only concern, then I would stick with the xm3 and save your money. All of the other incremental upgrades are expected by default in a maturing market, but for me it was only about the noise canceling.