I wanted an ultra sharp lens with a fairly wide angle for food photography and this does the job. A Not as sharp as the EFS-35mm I also bought but pretty close. The lens is beautifully built, fairly heavy (which I like actually) due to the thick heavy lens glass.

The optical quality of this lens is excellent. It allows you zoom from 17-55mm at a constant f2.8. Other zoom lenses will change the aperture but it can hold this constant as you zoom so it does not change your timing. The wide aperture makes it great for shooting parties indoors.

Consistent Output; Fast / accurate auto-focus; Nice Bokeh

Heavy

Nothing much to say. It's a great piece of glass that didn't get the "L" ring because it's EF-S, not because it's image quality lacks. Makes low-light photos easy with stabilization.

A quality modern mid range zoom for 1.6x crop with all the bells and whistles, constant F2.8, IS & USM. A bit soft at wide end at 2.8 which becomes sharper at f4. Like to see this lens upgraded to L quality for around the same price. Shoots good images but so does the 17-85 at f4.

Good images; IS; mid range zoom

Little Soft wide @2.8

Takes fantastic "L" quality shots. I can finally get wide shots up close. The only downside is the build quality. It isn't top of the line for ruggedness. I've heard that dust can get I side the lens, but I haven't had any issues myself. Overall I'm extremely happy with this lens.

This lens was a replacement for my kit lens. I'm more than happy with the lower apeture, and achieving a great balance for both indooor and out.

The lens is light, quiet, and is sharp; Very good lens for the price

Auto focus is a bit slow

Yes, I would recommend this to a friend

Fast / accurate auto-focus

Weak Casing

This is the best glass aside from the 10-22mm you can get for your Rebel. I have been able to borrow a friends lens and the clarity of the photos you will get from this far outweigh the cost.

daily walk around lens; portraits

I bought this new 17-55 f/2.8 IS lens to replace a previous one I purchased in early 2011. Over 7+ years I took about 16,000 images with the previous lens, about 1/4 of all my photos. The previous lens stopped focusing about a year ago.

old f3.5-5.6 wasn't fast enough to catch a 2 year old... this seems to have done the trick in low light! haven't really tried it out apart from that due to work and foul weather! so far so good! replacing kit lens.

Sharp Focus; Strong Construction