8 out of 10 points and recommendedBuild Quality, Weather Proofing, Corner Sharpness, Better Colour Rendition, Full FramePrice, Weight, IQ not as outstanding as I had thought
Not too happy with the kit-lens of my EOS 350D, I recently upgraded to the 17-40L. The first thing I did was compare this lens to the 18-55 II kit lens and to my astonishment, the difference in IQ between the two lenses was not as much as I had imagined and it was only after the comparison that I developed some respect for the kit lens! I realised that in some of my shots the kit lens (at f8) gave better center sharpness. Upon close inspection of several similar (outdoor) shots, I realised that the 17-40L gave overall better IQ, it has better corner sharpness and much, much better depth of field than the kit lens. Another strange thing that happened was that I used to almost always dial -0.3 exposure compensation with the kit lens, with the 17-40, exposure became more accurate and at times I had to overexpose! Between the two lenes, the 17-40 gave slightly warmer colours and slightly better dynamic range.reviewed April 17th, 2007 (purchased for $750)
Having used the two lenses, I know know that the kit lens is capable of producing great results and in image quality, the two lenses are not poles apart. In several subtle ways, the 17-40 is much better and beats the 18-55 hollow in terms of build quality, weather sealing, FTM focus and capability of being used on a full frame body. People living in fungus-prone, humid conditions might feel at ease with the weather sealing of this lens. Overall, the lens justifies its price and its place in any serious shooter's kit. Remember that with a build quality like this, it might serve you well for decades and so it is probably worth the extra $$ :-)
Lastly, I bought this lens after reading several reviews on this website. Thank you, everyone!
Jaipur (Rajasthan) India