I've only started using this lens a couple of days ago, so I can't say I have that much experience with it, but so far I am VERY PLEASED with it.
To begin with, its very lightweight, which is nice on the old Film-based Canon body. I have an EOS7 that weighs a ton.
Secondly, the lens is very sharp and I love the wide angle it gives. As this comes with a nice zoom to boot, I think I'm going to enjoy using it for a long time.

Edit: After having this lens for a while, I'm getting a little frustrated with the range and the iris. 28mm is not bad, but going out to 90 is often times close but not enough. If I could "do it again" i'd have sprung for a more telephoto lens. I still stand by the idea that the lens is good for beginners maybe marginally better than the "kit" 18-55mm lens, but again, you'll look to change it up soon after.

Original:
I am by no means a pro (or even a pro-sumer), but I think i was expecting a slightly wider range of zoom on this lens. 28mm is plenty wide for most applications, but I'm a nut for wiide shots and this didn't really do it for me. And the zoom gets you close, but you will probably be zooming with your feet to get that real shot you want. However, i wouldn't go much longer in zoom without looking at image stabilization.

As a beginner, I'm glad i got it because it has some range without doing all the work for you of considering your own placement in relation to the picture you want to capture. But I'm already looking for another lens.

After I ordered this lens I was a little worried that I made a mistake, that I probably wouldn't use it as much as the others.... I was definatly wrong! I love this lens and infact it has been on my Xti most over the others I have (50mm,75-300mm and the lens kit 18-55mm. It was well worth the $105.00 and for that price....really...why not get it!?

I am not a professional by any means but I have been very happy with the pictures I have taken with this lens.

This lens is a great value.
feels well constructed, opitical quality is good(could be better but not for the price range).
It's great for beginers or amatuers.

Used the lens for about 1 year and had no problems with it.
great range, 28mm is very wide on 35mm format cameras.
great walk around lens.
canon also has amazing online customer support.