Some early images with the 50f1.4.
As I mentioned in one of my other threads, the little sister lens (50mm f/1.8) is a great value but has some serious shortcomings for shooting macros. But what can you expect for $80.
So I picked up the f/1.4 version the other day. I thought long and hard about the f/1.2L version but decided against it. Some preliminary tests with the 50mm f/1.4 are pretty promising. Wide open at f/1.4, the images very close to that of the f/1.8 stopped down to f/2.8. The bokeh is much better with the f/1.4 version as is the construction and operation. The focus ring, although still too narrow and loose for my taste, turns nearly 200 degrees instead of the roughly 80 degrees of the f/1.8 version - making for better accuracy manual focusing.
What surprised me is that the f/1.4 does not improve in leaps and bounds as you stop down unlike the f/1.8 sibling. So by around f/5.6 or f/8, both lenses look very similar.
So the bottom line: is the f/1.4 worth the $320? Depends - that's why there are 3 versions of the 50mm :p For me and what I shoot and how I shoot it, it probably will. Still more testing to do.
The first image here at wide open f/1.4. Notice the bokeh. Love being able to get such narrow DOF when I want to without sacrificing too much in way of resolution.