Well I got a bit crazy this past week and sold off my 50mm 1.4 and the 100mm macro I’d traded for my 20mm 1.8.  My canon 50mm 1.4 was a good lens, it’s just that I’ve heard great things about the sigma so I figured I’d change things up a bit.  Basically the sigma is supposedly close to canon’s 50mm 1.2L in terms of IQ (and size/weight) but only costs $100 more than the canon while remaining a 1.4 max aperture.  It’s supposedly got some amazing bokeh, so I figured what the hell, why not try it?  I also shot with my 50mm more over vacation to prove to myself if it’s a FL I should keep.  I loved the shots I got, but I did notice if I opened up beyond 2.0 it was giving me some weird contrast/CA issues.  We’ll see how I do with the siggy, but I already love the size/weight of it (it’s very similar to my 24L in dimensions and my 24L is the “most comfortable” lens I own).