[boren]

I agree that overall the Sigma seems like a better choice, but having had compatibility issues with Sigma lenses in the past I'm not crazy about them. I much prefer Tamron and Tokina.



The IS is a potential deal-maker/deal-breaker. I don't have any stabilized lenses, but if the long-term reliability and higher tendency to de-centering are real issues then count me out. If these aren't real issues, then for sure I'd be happy to be able to decide which IS to use.