Hi. I used to fly with Dave Clarkes, then the Bose X, then the Bose A20. Also used 'company' Telex 750's and 850's. Then I got the UflyMike with the QC15. LOVED IT. I am now flying a large BizJet with the QC25 and UFlyMike Harmony. We have them as 'the aeroplane headsets' and they are very popular with the crew. The only comment we have is that the boom mike does tend to rotate away from your mouth as the friction on the mount is not enough. That said nobody wishes to change the headsets back to the Telex 850s..