I listened to PS100-500, it did not delight me in comparison with Yinman600.
But when my friend gave me PS100-500 to listen to on his amp Fiio A5 (800 mW @ 32Ω), I said wow, that sounded really cool.
yeah, the PS100-500 is more "bland" compared to the Yinman600. the Yinman has a warmer and enjoyable sound. if i can only have one earbuds, i would choose the Yinman for sure.
that being said, because i can have more than one earbuds for my collection, i prefer choosing the PS100-500 because of it's more neutral tuning, which is a more vacant space to fill among my collection.
but i do fancy those Yinman if it's available on my radar.
by the way, if I'm not mistaken, i think those Toneking TO400s has a similar sound to the Yinman 600? can't be sure though, because i tested them in two different occasions, never did a true head to head between them