50mm and 85mm are really different focal lengths, choose which suits the best your usage.
Buy one in second hand, and sell it at the same price if you're unhappy with it...
Thanks titi, I was really aiming for the 50 sigma and had read some issues on it that held me in purchasing the sigma.. But that was before. Now, I am just confirming its functionality on a 70d body. I do believe that 50 and 85 are different stories, I am after the bokeh this lenses could deliver. But of course, the versatility plays a big role on my decision.
EDIT: With all the sample photos (hoping Ive seen all non art versions), I am very sure that Ill love this lens. Thanks for the advice again.