I was using the WN-issued Telex 850, and bought the Bose QC25, waiting for the ‘Harmony’ product to be Fed certified (TSO’d?).
I must have waited 18-24 months without certification, so I elected to get the Bose A20. I am very pleased with the A20, although I can’t give a comparison to the QC25/UFly combo.
I just didn’t want the hassle of a line check with the non-TSO’d headset.