I picked up a 50 1.8 on the cheap today just to have a native lens thats small for walk around, and to see how the other focus modes act. To be honest, the eye focus is really cool, but the rest of the focus modes don't appeal to me much. The Sigma 50 art with the metabones on the latest firmware, is faster to AF and actually hunts much less than the Sony in low light. The sony is a really decent lens for less than $200 though!.
Heres a snap of my daughter with the lil' fifty








