Summary: After I left the store I get into the noisy subway station of NYC, and tried the headphones, it's was just amazing that it filter out a great amount of the background noise, and feel almost quiet like in a sound stage, after the music start to play, it sounded crisp and impressively lively.
Pros: Comfortable, Compact, Good Bass, Lightweight, Rich Sound
Summary: They are surpsisngly fun sounding and they give almost surround sound effect with detailed mids and good punchy bass and almost good for all genres music. The highs are not extended but overall they are detailed yet fun sounding and with good built quality. If compare to the X10i then X10i are more warm and very detailed in mids, more highs, with deep punchier bass than X5. But i find X5 are more fun, more balanced and very engaging IEMs.
Pros: surround sound effect, great mids, realy good punchy bass, crisp clear highs...