I have used the Telex 50D for the last two years in a variety of operations.
I have been VERY happy with them. By far the best combination of passive and active.
They are LARGE and they are heavy. But that's because of all the passive they have. They have more passive than regular David Clark's. So even without batteries they are better for your ears than a normal headset. This can't be said for many (any?) other ANR headsets.
Without the batteries it is just a normal headset. Which is good because I would always forget spares, or lose one of them, etc. This way I fly until the batteries die. Then recharge after that pairing.
If you plug in a phone / music player they will NOT auto-mute. Which is the way I like it. But a lot of people don't like it.
I have no experience with the other headset.