I just received my new Sigma 50mm 1.4. After reading a whole bunch of reviews and user experiences, I decided to roll the dice and hope that my 5D2's microadjust would be able to correct any focusing issues. Straight out of the box it was obvious that it wasn't focusing correctly. Did some more test shots and settled on +13. That's quite a bit of adjustment but now everything seems to be good. The colors are very nice--just like my L lenses. Just like what others have observed, the bokeh is really nice. From 1.4 to 2.8, there's some chromatics going on but it's negligible by f/4.