I've been flying for 5 yrs and have have worn a load of headsets during training, plus I went to a headset shop and tested a whole load of headsets against a background aircraft noise source.
The DC 13X (or similar, can't recall the exact name but it was about £500) was as quiet as the Bose, but with a much higher earcup pressure. It had better attenuation with power off, doubtless due to the higher earcup pressure and that's the tradeoff: if you want long-term comfort then you have to go for good ANR and the headset won't perform as well with no power.
I've done 6hr flights and have felt no discomfort. One could not do that with any other headset. Certainly not with anything from DC.
It's ridiculous to say
"Don't bother with Bose unless you have money running out of your ar5e, they are not worth the money and are utterly sh1te with ANR off."
when the cost of a Bose X is about 5 hours' UK self fly hire of a piece of old junk. If you have just got your PPL then there is about 90% chance you will drop out of flying within a year, so buying a Bose X (or anything else that's highly desirable to have e.g. a decent moving map GPS) probably IS a waste of money.
But for long term usage a Bose X cannot be beaten.
The other headsets, of which there are as many as there are Brietling watches and leather jackets, don't get anywhere near the Bose.
The drawback of a Bose is that you can't freely lend it to other people; it will soon come back wrecked. Or it will get nicked.
More generally, most non-aviation people think headsets cost £20 and it pays to brief passengers that actually they cost £700!
I've got four Bose X headsets, 3 of them have been modded for aircraft power, and I would never go back to anything else. An additional drawback of the aircraft powered version is the plastic Lemo connector which is relatively easy to break, and Lemo don't do a metal version.