6 out of 10 points and recommendedLight, good image quality, affordableveiled at wide apertures, AF mechanism problematic
Used on an APS-C body (in my case 40D) this is a great portrait lens, and therefore it quickly became my favorite lens.reviewed April 27th, 2011 (purchased for $400)
It has great pictorial quality, very nice colors, good contrast, but not at it's widest setting. Best used at f/2.8 and up.
However, my sample's AF mechanism broke completely after a small bump and the cost of repair was almost as a new lens. Afterwards I did some reading and found out it used an older type of USM mechanism that is more prone to malfunction and very vulnerable.
6 out of 10 points and recommendedAffordable, fastbokeh, lack of contrast
First the good points:reviewed April 27th, 2011 (purchased for $600)
It brings you the advantages of a fast fixed-aperture zoom at an unbeatable price.
It's very sharp, especially stopped down a little.
Great for a walk around or just getting your toe in the waters of professionalism.
But there remain the bad points:
The build is very poor, almost like a kit lens. The front plastic rim with the hood and filter threads loosens quickly and you have a feeling it will drop off any second. Focus ring moves when you autofocus and very often is just under your fingertips.
Although sharpness is great, it still lags behind the Canon affordable primes in contrast and color reproduction. Also, the out-of-focus highlights are very, very bad.
All in all, I found that I used it less and less when I had Canon 10-22, 28 1.8 and 50 1.4, was worried that it wont break apart and finally sold it.
However, I would still recommend it for a casual user who takes very good care about his equipment, want's a good traveling lens and is on a budget.