I looked extensively at test results (photozone.de and slrgear.com) before buying. The interesting thing is that the f/1.8 "nifty fifty" has basically the same performance wide open as the f/1.4 stopped down to 1.8. So...US$75 for a 1.8 that's usable (barely) wide open, or US$305 for a 1.4 that's only usable at 1.8 and narrower. Hmmm...that's not too hard...
Except the AF in the 50 1.4 actually works sometimes
(exagerating a bit , but the 50 1.8 AF is the worst I have experienced))
Then there is the ugly blur of the 50 1.8 (IMHO)


..... 
