They are AMAZING headphones, if you like neutrality and clear audio, there is really no competitor, Grados 325e? Not even close, Audio technica r70x? You're kidding me. I can't emphasize enough, YOU NEED THESE HEADPHONES, they make sub-par songs sound great, you will love them, no matter how expensive your current headphones are. No more needs to be said....                       HURRY UP AND GET THEM!

Yamaha mt220's are amazing headphones which offer top notch sound quality for little expense. They do net need an amp to drive, but still work well with one. Neutral sounding while still maintaining a good, realistic sound. They blow the m50x out of the water, if you are looking for a cheap set of cans with pristine quality look no further.

If you are willing to put aside comfort and bass for a clearer sound the sr325e are for you, the sound signature takes some time to get used to. Highly recommend listening to them before purchasing, You might totally hate them. You most likely won't enjoy the Grados without an amp and a recording above 320kb/s, they are pricy but if the sound suits you, you may prefer them over much more expensive headphones, so it's really best to have a listen to them along with the 80's and 125's just to see how much you are willing to pay for the subtle...

If you are looking for a portable bluetooth headphone willing to compromise some sound quality for it then look no further, they are not too pricy, but i really expect more for sony in terms of sound quality. If you are serious about audio you probably won't like them. But audio is a subjective topic, so you might strongly disagree and end up loving them, that's just my opinion.