I've read that Sigma lens have QC issues. I'm particularly interested in the Sigma 10-20mm F4-5.6 EX DC HSM (Canon Mount) lens.
Are these QC issues are thing of the past? If there are still issues with the QC, what should I be looking out for other than "overall softness" and
"softer down the left hand edge than the right hand edge, of a landscape shot"
*Did some googling, but many commented on the QC issues, but not things to lookout for...*
Would appreciate any precious feedback regarding this.