Thanks for all the replies. Interesting to see the same kind of polar opposite opinions here that I've seen elsewhere. I know there are a few (three?) separate species of cleaner wrasse, and also some very similar looking goby species, I wonder if this has anything to do with reports of success? Perhaps not, though, as I have read accounts of moorish idols who will eat anything and have lived for years. Could be normal variation.
I've seen those cleaner shrimp in stores before, but didn't know they could clean off ich parasites, very interesting.