I own a pair and think they have a narrow use band.
They have no soundstage, a mid-fi lower mid and upper bass hump, and they are unfocused. Instruments have a unique and bad quality. All sound as if you are inside the instrument, but the soundstage of each one is a huge blob in a general direction. So when you focus on an instrument it is 'somewhere over there' but what you hear sounds like you are inside the guitar, or kick drum, etc.
That said, for a portable that you don't think about they are very good. Deep sub-bass, comfortable, they fold up, the tonal accuracy of each instrument is excellent, and they make all music sound good within their limitations.
Just don't compare them to anything better.