Hey @HI Zz - If you aren't enjoying the frequency response of your Westone 3, it might not be the IEM for you. You can use the EQ functions of your IMOD (which, might be easier with ROCKBOX) if you would like to alter the signature.
For me, Comply tips are best - no effect on highs from my perspective. Just a better fit.
They will only "hiss" if your source has a high output impedance. Alternatively, the tracks your using might not be mastered correctly - are you experiencing the issue with all music, or just one album? What sources have you tried?
The Fiio E10 isn't great for IEM use - the output impedance is too high, and you will experience hiss.
Thanks for the reply. Do you mean the P series complys?