proxus, check out the Clarity Aloft headset. I'm looking at it possibly myself. Have a few collegues using it and they love it. If you don't mind putting things into your ears that is, it's really light, doesn't go over your head and messing out the hairdoo and the noice cancellation is apparently reeeally good. Should be perfect for the very loud 757 flightdeck, especially certain X 757-300's and the cargo ones
Then you can just pull out the left ear plug and it just hangs, should you need to speak to someone directly or the older guy in the other seat, so no re-adjusting the headset all the time. I thought some of the 757's had intercom?
I have not tried this HMEC 27-T but it looks really nice, but I have tried the HMEC 46 which is somewhat different I guess but I hated it, my ears got sore on the longer flights.