I have been using the Pro-X for many years, but for some reason on one side of the airplane I just started flying, they cause a buzzing in the intercom. I sent them back to DC, but I decided to look around for another headset to use. I find the Telex 750 and 850 to be very uncomfortable to me, so I tried the Zulu 3, the Bose A20 and the DC One-X. I ended up keeping the One-X over both of those headsets. They are far more comfortable (for me) than the Zulu 3, and I found them more comfortable and better made than the A20's. It doesn't hurt that they are $100 cheaper than the Bose, and only slightly more than the Z3. Bonus is that they are 100% made in the USA. I just got my Pro-X's back from DC but I have not had a chance to try them out in the airplane to see if they were fixed. DC replaced a whole bunch of stuff on them for completely free.