All the reviews read on this perspective javais placed him at the head of 50 mm all brands. After numerous photos taken with this goal, I am not disappointed by the quality regarding the definition example (Very good 1.4 to 2.8 and then to 11 good, much better than the Canon 24-70 / 2.8 at this focal). Of course it is heavy and bulky for a 50 mm, but for me it is secondary default face his stunning pole! Especially at Canon, the 50 mm does not mattiraient (the 1.4 too old, all plastic 1.8 and 1.2 require close to 2.8 to benefit from a good quality.
Congratulations to sigma for the quality of its range Art!