The 50L is the sharpest 50mm canon makes in the center from F1.2-2.8. If this fits your usage, I'd get one.
LOL I loved my 50L very much, and it was a lot of things, but not extraordinarily sharp. And for the record the 50mm f/1.4 is sharper than the 1.2 in the center and MUCH sharper on the edges. The edges on the 50L are HORRIBLE, they barely even register on the chart. I've heard some say that they were going for that kind of soft edge effect for portraits, but either way when I got my Zeiss 50 f/2 I realized just how bad the Canon was on the edges. When I jumped from the 50mm f/1.4 to 50mm f/1.2 I didn't notice any change in sharpness, the most noticeable differences are in the bokeh, color rendition, AF speed, and build quality.
Here is the 50mm f/1.4 compared to the 1.2:
It depends how good, bad, or ugly the copy you received was. Mine is superior to any of my previous 50mm I've owned and TDP shows how terrible the 1.4 is with CA and Veiling haze. It mirrors my experience in the center where it matters most to me.
Now most here don't care for Mr. rockwell but his experiences mirror mine with the 50L in usage. It even demonstrates the zeiss vs 50L in veiling haze.
Nailing focus is key @ f/1.2 and when it does, I'd never go back to another 50mm lens.