Making a case for hyphenation

I'm laying out a newletter/magazine, and the client recently asked to remove all hyphens from the text (which is left-justified).

My feeling is that hyphens improve legibility by leading the eye and allowing for a more even and less jumpy rag. I was thinking about my rationale today and realized I have no proof to back up the legibility angle. Was wondering if anyone knows of any studies that have been done on the topic or if there is any science (psuedo or otherwise) that I could use to defend my preference for hyphenating text. If I can make the case for improved legibility I think it will be easier persuade the client.

Thanks, eh!