Thank you for reminding me those thread on MX75 foams. They are comfortable indeed and I like to recommend them. Just added link to OP:
MX75 foams - recommended for PK1, PK2 and other earbuds
MX75 foams - recommended for PK1, PK2 and other earbuds

















. Mix the description above with these to get the whole picture: "Sound is balanced, fun and energetic. Details are ok, mids are forward and smooth. Bass is not deep, but punchy. Highs are fine, no hisses. It seems that very high frequencies are recessed. Probably this is the reason for sound imaging to be so-so."

