let start off with the bass. The bass extension of H3 dug deeper and each bass note hits with more authority than the ZS5. This is a must especially since H3 is more expensive than the ZS5. To sum it up, H3's bass is cleaner and extended deeper. Next, we have the mids section, ZS5 mids is not as clear as the H3. The H3 presents the midrange in a transparent manner for vocals to shine. The micro details on the H3 is far more superior to the ZS5. In my review, I compared the H3 with more expensive iems and you can see H3 can compete with them but definitely not on all fronts. Moving up to the highs, H3 treble is not grainy at all while on the ZS5, I feel the grain and there is not much of a clean bite. The extension of H3 is better with more air too. Soundstage wise, in terms of width or depth, H3 has the upper hand. Cheers.