I definitely recommend buying, I didn't notice any disadvantages.
For a long time I did not know what to choose from 50 When I found out about this lens,
View test portraits (in conjunction with 5d2; development in ACR without retouching) here:
Pros
1) High sharpness already from 1.4
2) Autofocus is fast, accurate and silent
3) Beautiful drawing and bokeh
4) Good body
5) Small achromatic and distortion
6) Holds backlight well
7) Stability of workmanship (unlike Sigma AF 50mm f/1.4 EX DG HSM)