Yes, I read the LensRentals analysis some time ago, and I haven't had dust issues myself. I'm sure that there are some who exaggerate the issue, and probably a few malicious individuals searching for a reason to denigrate Canon glass for whatever reason. Also, there will be natural worriers who may be influenced by internet talk. Personally, if Canon gave me the choice between a telescopic zoom and an internal zoom, for comparable size and cost, and with the same MFD, I'd go for the internal one though - I just think it's a better design.According to LensRentals, they don't have more dust issues with pump-zooms than with the other type. It seems to be a psychological issue more than a real one.