I have the ZSA and ZS6. The ZS6 clearly sounds better but its a model I never recommend because its a ergonomic nightmare, so I never recommend them The ZSA doesnt have this prpblem but its bass never convinced me. I prefer the ZSN Pro or a TRN V80 that have a similar driver configuration than the ZS6, is way cheaper and its finish is top notch. Even with a defective (loose) connector, I 2nd the amazing build quality... But its song signature never convinced me, but now I wanna give it a 2nd chance.