Great summary, i oso did a comparison in dpreview website for both lenSES.Check this out:
http://www.the-digital-picture.com/...&Camera=453&Sample=0&FLI=0&API=0&LensComp=115
I own Canon 1.4, but I'm planning to trade it for Sigma. Haven't done that coz I don't use 50mm alot nowadays (enjoying MF on 90mm tse too much)
Sigma
Adv: Much better sharpness for larger apperture f/1.4 - f/2, nice bokeh less distracting than Canon (but bokeh is always matter of taste)
Dis: Bigger, more expensive, less accurate AF, less sharp in the corner for full frame
Canon:
Adv: More accurate AF, smaller, sharper in the corner on smaller appertures
Dis: hazy on f/1.4 - f/2
Both lenses have adv and disadv, so none is better than the other
If you use 50mm for studio shots, using F/8-F/11, the canon would be a better choice
If you use it for landscape, canon wins again
If you use it for portrait using f/1.4 - f/2.8, sigma wins
etc.
canon len do produce nice pic for protrait. i not a serious photographer but i do notice the dif. By comparing the value and the adv, i kinda find canon more worth while, maybe my perspective is different from you guys

but then rumour say got mark II, i shall wait and see the review. maybe it better? more ex?
