I have no knowledge about headphones, I bought these specifically to connect to the Axe-Fx III and play my electric guitar because I moved to an apartment building and didn't want to have issues with the neighbors. I was pleasantly surprised by the sound quality, I think it's a great choice for a guitarist who has guitar modelers. The clean tones are incredible, the scooped mids are somewhat average, but overall I am very satisfied with them!

After extensive market research, perhaps my best choice is to have proper amp/dac drivers and be able to comfortably drive the 250 ohm

It is difficult to find headphones like this, it is the perfect tool for working on sound mixing, etc.
Amazing build quality (no comparison to the unacceptable plastic of the 770 990, etc.) The cable is also much superior to Hifiman, for example... The earpads and the 2 drivers scream quality and are very comfortable, much more comfortable than the few headphones that have such a large soundstage, although personally I don't like the round earcups because they touch the jaw, like the Sundara, for example... I like the earshape like Ananda, HD660s, etc.
Balanced doesn't work here, many have made mods, personally I didn't go through the process, some don't want crazy power to play, definitely less than HD600, Sundara, slightly below 660s.
With IFI zen, micro, nano, Fio k5 pro, they have air.
These have resolution, resolution, resolution, they go quite deep, they don't have the depth of the Sundara or the bass texture of the HD660s, but they definitely have the impact punch, obviously due to their semi-open construction, they don't have the leakage of the others.
Now, what someone needs to know before getting them, the mids are not what someone expects if they have heard other headphones like HD600, 650, 660, Clear, Sundara, Ananda, not that they don't have the technical background, quite the opposite, it's just that due to their signature, they are behind in presentation (we can't have it all).
The highs are detailed, as everyone knows, but quite fatiguing when listening to not-so-good quality recordings or a specific genre of music with emphasis there, combined with the distant mids, the result worsens, the very good thing is the soundstage, which I would say is even bigger than Sundara's. It is on the level of HD700, for someone to understand, usually headphones with such a large stage also have their spikes in the highs, so this is logical as well.

Final verdict, it is the best for professional use and maybe for some gamers who want a large soundstage and to hear footsteps. However, it is not the best for music listening, the reasons being that there is no warmth, there are no smooth highs to help with bad recordings and all music genres, for example, HD650. Also, the huge soundstage is not an advantage in recordings with many vocals, where the mids are gathered, there is also the openness of the stage, it's like you hear the singer behind the instruments.

Perfect as a tool, average for music listening.

My headphone collection includes all the expensive ones up to $3500 abroad, Electrostatic, Orthodynamic, and Dynamic headphones. The BeyerDynamic DT 1990 is by far the best, followed by the 990 Pro and the 770 Pro 80 Ohm. I haven't acquired or listened to the T1 yet, which they say is better.

If you want to relax after a hard day's work, take a Sennheiser and it will put you to sleep in a few minutes. If you want to go to a live concert, take the 1990 DT.

Only if you have a limited budget, take the 990 Pro. The difference is significant in terms of resolution, distortion, maximum volume, and efficiency. Significant not only in terms of characteristics but also immediately in practice once you wear them and listen to them.

The set, although quite impressive with a $300 Sony Walkman, is greatly improved with a $1000+ DAC and literally elevated with amplifiers > 6 Watt (~$400).

Also, even though it "resembles" live with the VLC Player, it "imitates" live using many renowned software VST plugins simulating legendary hardware mixing and mastering equipment.

It comes with two sets of pads, Balanced and Analytical. It should have a third one somewhere in the middle. Fortunately, there are easy ways to make reversible modifications to achieve the desired performance by adding small pieces of insulating tape to the pad holes or by adding foam rings under the pads.

Finally, its durability and reliability are unmatched compared to the others despite its low price. It simply outshines them.

It's not a coincidence that the majority of professionals choose it. The fact that most audiophiles don't choose it is because most audiophiles are audio fools.

I won't say much, after all the reviews are on the internet and anyone can see them. I will only say that using the (A)nalytical and (B)alanced pads is like having two different headphones at your disposal. And if you want my opinion, don't waste these headphones with the balanced ones, no matter what you read. The resolution of the analytical ones is simply amazing for a 400 euro headphone. The imaging and sound separation are also very good. I give it 4 stars because the mids are slightly recessed, but I'm waiting for Dekoni pads to help with that. Also, the soundstage is quite good, but not excellent. They are a bit bright headphones, which means that with certain songs they can become tiring after a while, but overall they are very good headphones and personally I only use them with analytical pads.
With the B pads, they remind me of V-shaped headphones that cost 200 euros and nothing more.
The build quality is simply... Germany. From the headband to the arms and the cups. And also, at this price they come with a carrying case, two cables, and the pads as I mentioned.
4 stars for the price, which could be a bit lower, and because they are a bit brighter than I would like them to be.