8 out of 10 points and recommendedIS, large focal range, fast autofocusf4-45.6 is pretty slow, noticeable CA and distortion (not too terrible)
I got this lens as part of a kit with my 20D and as a result, I'm not sure how much I actually spent on this lens (bought it last year). It is definitely better than the normal kit lens, which is a EF-S 18-55 f3.5-f5.6.reviewed December 27th, 2006 (purchased for $600)
The EF-S 17-85 looks great on paper because of the IS, autofocus motor, and the very usable focal range, and those are the greatest selling points. The IS works great for minor shake, especially if you keep forgetting to buy a tripod like me, he USM autofocus is very fast, although my lens takes longer when there is not a lot of light, and lastly the range on this lens is amazing as an everyday lens. It has become extremely useful to me since I will sometimes shoot scenes and then decide to shoot closeup later in the day. I really haven't needed another lens for a while.
However, one should watch out for a few things. I've noticed a decent amount of CA and distortion when using this lens zoomed all the way out. It isn't awful, but it is prety noticeable. The lens produces some great bokeh, but it would be easier to take advantage of the bokeh if the lens were a little faster.
The lens is great though if one remembers the few shortcomings. There are better lenses, but they also might cost more.
10 out of 10 points and recommendedFast lens, great bokeh, colors are amazing, out resolves my 20DNo auto focus, no image stabilization, unable to sync to Canon cameras
I'm extremely pleased with this lens. Picking up the lens gives a feeling of reliability because the construction is rock solid. The f/1.4 is wonderful but usually leaves too much out of focus! I usually stop down to f/2.8 when I use this lens. In any case, the bokeh is great, as are colors. It makes for some nice portraits.reviewed October 28th, 2007 (purchased for $500)
Unfortunately, the lens has no autofocus system and no image stabilization, so if you've gotten too hooked on those, it may be difficult to transition here. Plus, the lens only mounts via adapter to Canon bodies, and the camera won't recognize aperture size in the picture info.
Even so, I love this lens and recommend it. Unless autofocus is a necessity. This is my second lens, with my first being the EF-S 17-85 f/4.0-5.6