EF 17-40mm on Rebel XS

Hi

I also agree that you go with the Efs 17-55, after many years this is still my favourite Lens.

The dust issue I believe is a thing of the past, I have one of the earlier versions and did have a lot of dust inside; I  stripped it down cleaned it myself, the fault lay with the front seal. This was borne out by the fact that since cleaning and re-seating the seal and fitting a UV filter, I've not had a speck of dust inside since!

If you ever go full frame in the future, the Efs 17-55 will still fetch good money on eBay!

Best of luck with your decision.

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Chrislofotos
http://www.chrislofotos.org