Summary: It’s a valid point, but there’s still benefits to having a brighter lens with a digital SLR. First, the smaller focal ratio and circular aperture of the 17-55mm allows it to deliver shorter depths of fields with more pleasing bokehs than other EF-S lenses, making it ideal for portrait or dramatic...
Pros: Bright f2.8 aperture throughout zoom range, Effective anti-shake IS capability, Fast and quiet USM focusing motor, Superb low-light performance
Cons: Relatively expensive, Construction not Canon L standard yet, Range shorter than cheaper EF-S 17-85mm, Lens hood and pouch are not included
Conclusion: The Canon EF-S 17-55mm f/2.8 USM IS is not a perfect lens but it lives quite well up to the very high expectations of the user base. The resolution figures are among the very best for an APS-C standard zoom lens.