The AKG K-240 MKII were not my first choice. Actually, I wanted the much more expensive BeyerDynamic DT 770 Pro (80 Ohms), but the store where I placed the order couldn't process it, so I went with the AKG, since I didn't want to spend 100-120 euros on headphones that weren't my first choice.

After a month of having them, I am particularly satisfied, as long as we judge them based on their characteristics. That is:

They are semi-open headphones, so they won't isolate external sounds. They also won't give you the feeling that the sound is "hitting" your head. You mostly feel like you're between two speakers.

The sound quality is very good, as long as you're not looking for super bass. The 240s don't aim to sound nice and impressive, but rather flat and faithful to the recording.

Their "drive" is quite easy. I often connect them directly to my phone and they play exceptionally well without any additional amplification. Of course, with a headphone amplifier, the sound quality improves, but it's not necessary.

As for comfort, let me start with AKG's system (which works like there are springs) that makes the headphones sit in the right position on their own. The weight of the left earcup is a negative aspect, possibly due to the cable. I also have the impression that they easily cause sweating, and I'm afraid to think about what will happen if the temperature rises.

As for the quality, I can't speak yet. It's too early.

I have had these headphones for years, both these and the K240 Studio. They are the same, the only difference is the color and that with the MKII you get an extra cable (spiral) and fabric pads. The sound is the classic AKG sound, so don't expect a lot of bass. They have been around for decades and many people use them for many years without any problems. They have a simple plastic minimalist design that may not look "fancy," but they are more durable than they appear as long as you take care of them, of course. The fact that they are now Made in China and not Made in Austria like before may be the reason for reports that some of them break or stop working after a while. Maybe, I say, because I have never had any issues with my China Made 240s, but I take very good care of my headphones. It's possible that some "lemons" are produced, and if you're unlucky, you got one of them. Obviously, the quality control is not the same as headphones that cost multiple times the price. If the original leather pads are not comfortable for you, you can replace them with the velour pads from the Beyer DT770, which are perhaps the best in the world. However, keep in mind that the sound will change, and whether you will like it or not is a matter of personal taste.

They have not been praised by hi-fi magazines, but I like them.
I have had them for a very long time and I haven't listened to them in a very long time (we're talking about years), but I will try to give you an idea of how they play.
They sound comfortable, effortless, natural, airy, and relaxed. They don't have seismic bass, they don't rely on it, but on the aforementioned qualities. You feel pleasure and relaxation when you listen to them.
They have been criticized for having a somewhat conservative, not realistic sound, with some lack of the nerve and intensity of real music.
And because I read somewhere about the treble peak of AKG, I should say that I also noticed a slight boost and a "pinch" of metallic sound in the highs, which I think works positively because it adds some liveliness and intensity to the sound and makes it slightly more exciting. It probably enhances your interest. In other words, if it didn't exist, something might be missing from what is there now.
I'm sure that if I listen to better headphones in this category, I will understand that I'm listening to something better and I will accept what many expert reviews say, but nevertheless, I want these AKG headphones to exist (and have them) because I like them just the way they are and for what they are. So the stars I give are something subjective and it's better to pay attention to my description.
With 74 euros that they are currently being sold, they are much cheaper than before.
I believe that the company hasn't improved and changed them much, and I'm saying irrelevant things. They have the same name, so they must be basically the same.
I didn't know how to rate comfort because I never listened to them for so long to understand what would bother me, but it seemed to me that something would "come out" after prolonged listening. I can't say that I felt like I wasn't wearing headphones and that nothing was bothering me, but I felt like I had limited time to accept them unquestioningly. However, I can't say that they fit well in the ears either.
And to tell you the truth, even though the headphone and sound chapter has obviously made significant progress over the years, only the comfort issue on the head would make me, not forget them, but put them aside a bit, for some other super-comfortable and convenient ones that I can wear and listen to for 10 hours straight without realizing that something bothers me.
S.D.

Quite to very good sound quality, depending on preference.
Excellent value for money, it is over-ear, semi-open, so it is also suitable for office use as it does not have a high sound leakage. It does not necessarily require amplification, but amplification definitely helps.
It does not have bass that causes earthquakes (personally, it does not bother me at all), it has the AKG home sound with the well-known treble peak (which for some reason only bothers me in my right ear, which is sensitive and only in some recordings). It has very good instrument separation, but unfortunately, many people on head-fi and Amazon mention mediocre build quality. Personally, I did not find anything bad in terms of construction, but it is still early. Generally, if you find it for around 80-85 euros, it is a very good purchase for someone who does not want headphones for outdoor use or headphones with deep bass. If they also like classical music, even better, but I did not miss anything in other genres that I listened to (rock, folk, blues, and jazz).

I have had these headphones for four and a half years. Their positive aspect is the sound quality, which is very good, especially if someone wants them for a home studio.
However, their negative aspects are the following:
1) The quality of the plastics is very poor. After a year and a half of very careful use, a small plastic piece that held the right earphone broke, causing it to detach and hang. However, I fixed it with an invention, I screwed it with a screw! Additionally, despite my careful use, the external plastic covers of the headphones cracked and then came off, but I glued them back on! When I reported these problems to the headphones' representative in Greece, they refused to repair them, claiming that the warranty period had expired, which according to the representative was only one year, but according to European legislation and according to the AKG website, the warranty was two years. Generally, from what I see, most online stores do not state how long the product warranty lasts. The interested party will usually find out if a problem arises!
2) After 3 years of use, the right earphone started to have interruptions in the sound. And recently, the same right earphone hardly produces any sound at all. In order to get sound, I have to change its position a thousand times on my ear, and once I find the right position that establishes a connection and has sound, I have to remain completely still to prevent the sound from stopping!
3) When someone wears these headphones for a long time, their ears sweat inside the earphone (especially in the summer!). Generally, they are a bit tight and a bit tiring to wear for a long time. But I imagine they are tight and tiring because they are designed for professional or semi-professional use. I think they are not suitable for those who simply want good headphones to listen to music for their enjoyment, as they will tire them out.
Due to the lack of quality in the materials of these headphones, I was disappointed, despite their excellent sound quality. Because they are expensive headphones. And when you buy an expensive product, you expect to have it for many years. Soon, if I don't find a solution with some invention regarding the sound of the right earphone, I will have to buy another pair of headphones, but probably not from this brand!