Tried both the DC X11 and the Bose over a 15 hour holiday trip. Short
version: The DC got returned and I'm keeping the Bose. It wasn't a
tough call in my mind.

Longer version: I've had a DC H10-80 for 17 years now. About 10 years
ago I had Headsets Inc add their ANR kit to it. That all continues to
work fine, but it does get tiring after 6 hours or so due to the weight
and clamping.

I liked the DC X 11 in the shop, but their reviews I've seen have been
somewhat negative. So I got a set and a set of the Bose and compared them
on the trip.

Compared to my old H10-80s, both the X 11 and the Bose are lighter, have
significantly less perceived clamping pressure, and more effective ANR.
So state of the are has evidently advanced.

I really wanted to like the X 11s - some nice added features and less
money. I found the ANR on the X 11s to be less effective than the Bose,
and the speakers to produce sound that was "thinner" - less full and rich.

But for our needs the X 11 was useless. It evidently depends on a very
tight/effective seal on your head. If that seal is disturbed - even by
turning your head and flexing - the X 11s will 'thum'. That is
somewhat annoying, but if you wear glasses - as both of us do - you can't
get a consistent seal, and the slightest movement causes the 'thum'.
Short of holding both hands over your ears and applying constant
significant pressure to the headset, I don't see a way these can be used
with glasses.

The Bose, by contrast, doesn't 'thum'. If the seal on the Bose is less
than perfect - due to glasses or movement - their white noise level simply
increases slightly. Noticeable if you're looking for it but not annoying.

I like the music and phone inputs on the DC and their price, and my DCs
have been good to me - but the fact that the X 11s simply 'don't work'
in my environment negates all of that.

The Bose has better/fuller sound, better (to me) ANR, and works with no
fuss or muss.

We kept the Bose. It was an easy decision.