9 out of 10 points and recommendedDepth of field, pleasing bokeh, full time manual, HSM, case and hood includedChromatic aberration, APS-C only, vignetting
Got this for my 600D to get a 'normal' lens as I deemed it better than Canon's 28mm. Very impressed with it. Some of the cons like chromatic aberration and vignetting are found on a lot of fast primes so not really a fault of this particular lens only. The inclusion of a soft lens case and lens hood (as with all Sigma lenses) is a definite bonus and played a big part in me buying this over Canon's 28mm.reviewed February 16th, 2013 (purchased for $350)
Although I said I'd recommend this lens, with the new 30mm due out any time now, I'd recommend waiting for that one as it's compatible with the new usb dock and is supposed to have better handling of CA.
8 out of 10 points and recommendedPrice, macro, pleasing bokeh, 1.8 apperturefocus ring travel, lens breathing, no HSM, CA.
I'm using this with a Canon 600D/Rebel T3i.reviewed April 5th, 2013 (purchased for $400)
For the price, this lens is a true bargain. It offers wide angle (or wide-normal on crop) and macro (not true 1:1) which is a welcome bonus. The bokeh is pleasing enough and shallow depth of field great for arty shots. On the downside, the front element extends when focusing meaning you get quite extreme lens breathing. Also the focus ring travel (rotation) isn't that great (about 90 degrees), meaning manual focus is fairly tricky as slight movements will throw the focus out easily (this issue applies to other Sigma's I've owned). The lack of a silent focus motor (HSM) means this lens is both noisy and slow to auto focus. There's also a fair bit of CA at higher f numbers but this can also apply to other fast primes regardless of price so cant complain too much here.
Overall I am pleased with this lens. The only main gripe for me is the focus travel issue as it would be nice to be able to better control manual focus. Other than that, I can't fault this lens too much as all lenses at lower price brackets will have their issues and compromises. I cannot justify the price for Canon L series lenses and the macro and f1.8 make this 24mm the best non-L alternative.