I use the AKG K-271 MKII headphones with my Yamaha THR10 amp while playing quitar at home for not to disturb my family. For this kind of use the headphones are excellent. As the headphones have basicly a flat eq curve from low frequencies to the high treble, they are very suitable for monitoring ? for which I used them also in my past occupation in radio some time ago. Actually I feel that with these headphone I can distinguish the effect of minor amp adjustments more precisely than from the loudspeaker of the small amp itself.
If you are looking to buy them for hifi use, outside of classical music you may be disappointed to the non-amplified base, but in classical music you would value the preciseness of these headphones.
The are so comfortable on your head that one easily forgets any recommendation for not to listen with headphones on for more that an hour a day, one simply forgets that the headphones are there. The cord length was enough, though to increase freedom of movement I also purchased an extension cord.
The package had also replacement ear pads, so I expect to be using these for a long time.
Definitely a good purchase for a monitoring purpose.