I wear the Telex 850 ANR the entire flight. And I don't think anyone cares if you wear it all day long.
The A320 is a quiet cockpit, but I flew it my first year with headsets off above 18k and on below 18k. Then I got the 850 ANR and have flown it now for another year and I must say I noticed a significant reduction in noise with this headset. I'm happy with this. 36 years of professional flying left (hopefully) which means protecting hearing is of utmost importance.
I love having great conversation in cruise about all manner of things, but I,ve always done it through a boom mike and a high quality ANR headset.
I also admit I like hearing ATC in the same way and responding with a simple push to talk button as opposed to a speaker and hand mike. Seems less stressful and feels like less work.
You can't force the guy sitting next to you to wear a headset too. With a Telex 850, I can still hear the other guy like normal. I keep the radios down (usually down to almost minimum because with the headset on, that's all you need). To talk to ATC, I use the headset boom and push to talk trigger. To talk to the other pilot I just talk like normal. It works fine with that way with the Telex 850.