I've had mine for at least 3 years now and I'll say they are worth every penny. I'm not pretentious enough to say anything specific about the sound quality since I'm no audiophile but they sound amazing to me.
The mic is absolutely outstanding and will probably beat at least 9/10 headsets. Most people comment on my mic quality and all I do is just plug and play.
Comfort-wise, they are super light and I can go for long periods of time with them on without an issue.
I will note that I swapped out the pads for some more premium ones (mostly because I could rather than out of necessity), but the stock pads are fine. I also owned the older generation AG1 (closed version) and the (fake leather) pads then did kinda rub on the area in front of my ears (between temple and ears) because of my glasses and my hair. I don't recall having that issue with the ADG1X, maybe because of the velour pads, but I definitely don't have that issue now that I swapped them out.
Some minor issues I have with them over the years:
1. The cable isn't detachable and is only on the mic side (left when on) so I'm limited on how I can place my computer.
2. The headband design, or lack there-of, makes them a little annoying to get a stand for but I currently have them sitting on a Brainwavz Hooka perfectly fine.
3. Not really a portable option since they don't fold, come with a case, and the mic isn't detachable.
If you have anything else you'd like to know or if you wanna see how they've been holding up (basically pristine, great build quality despite being at least half plastic), lemme know.
I got them for I think almost 200USD back then on sale but I would easily have paid full price.