This is my favorite lens which would be my most favorite lens when I get the 6D. Currently, it's the 28mm F1.8 due to the crop factor but I expect that this will be very much used when I get the 6D. I love this lens for portraits on an APS-C. If you can't get excellent shots from this lens, then you've got a problem. No one can ever blame this lens for taking the best pictures even at the least price.
Here's some of my recent shots: