Well that’s the fun of the hobby
Don’t get me wrong, I don’t think c201 is not natural sounding, it is and it’s also on the warmish side of sound but it’s definitely less sweet and more energetic than dx340.
Especially with dx340 set with filter h2.
To my ears and with my iems/hps, dx340 is more neutral, sweeter, calmer while N6iii is more energetic both in bass and treble.
Also, the soundstage of dx340 is bigger (that soundstage is enormous), while N6iii bass is stronger and treble has more sparkle. So it really comes to preferences/pairings I must say. Of course IMHO, to my ears etc etc.
Happy to have both