I think the lacquered cymbals (like Paiste Signatures) should definitely be cleaned (though I haven't cleaned mine in over a year.
I have some 1970s vintage Zildjian A's that I
have cleaned (last time was 5 or 6 years ago) and a couple of K Custom Dark rides I'll probably never clean.
I also have some Paiste Traditionals and Sound Formulas that I'm planning to clean this week when I clean the Signatures (just bought the Paiste cleaner).
Don't know how I'll feel when I get my hands on some Istanbuls and Bosphorus cymbals.
Can ya tell I didn't vote in the poll?