ED9 cables are as cheap as it can get, even the metal housing finish ain't great. The blue and red rings on the IEMs fade in no time. And I hate bright and forward sound signature which is exactly what the ED9 has. I love a sound signature which ain't too bright and fatiguing and has richness warmth and a TAD laidback , this makes the soundstage more palpable. Piston 3 has signature very close to that. Piston 3 ain't the greatest but to me they are better over the ED9. Sound is subjective and to each his own. The only Knowledge I liked was the ATE. Really worth every penny.
I'll beg to differ with you on that...
I think the ED9 has a great build quality compared to the pistons (am comparing with the piston 2)... Most of the piston 2s that I have seen have got damaged even after all that Kevlar mumbo jumbo and what not... Typical Xiaomi!!! Same thing happens with their mobiles and tablets...
No idea about the piston 3 though...
Also, don't know whether the KZ ED9 will survive rough handling but in the two weeks that I have been using it, it's impressed me with its build quality...
I am not that rough a user so if you are the type who perform experiments with your IEMs, none will survive... Unless you get some real expensive $h!t...
About the sound signature, its really subjective and varies from person to person... But, what's good with the ED9 is that you get two filters, i.e., two sound signatures, viz., an okay bass heavy filter and a mind-blowing neutral filter...
The main thing is that without auditioning the ED9 or the piston 3 in person, a layman won't be able to differentiate which is better...
My advice to any of you guys who are in a dilemma of which to buy, just buy one of the two... They will anyway have a much superior sound quality than the IEMs you are currently using...
About build quality, that's subjective too and varies from person to person... Some of the other forum members ES18 or EM1 went kaput in a couple of weeks, some have continued to survive for years!!!