[JJ_SO]

I'd say that a f/2.8 lens is usually always better than a f/1.8 lens.

 

I doubt this statement, especially because you can't decide between "always" and "usually". Either one or the other 

 

I also doubt that in terms of bokeh there are a lot of 70-200 lenses beating this Sigma speciality. But I think one needs to decide: For portraits FF and a zoom - hands off the Sigma 50-100. For APS-C a very nice portrait zoom: very different story, although same weight, same price. I'd at least give it a try before I'd say no to it. And I would use FF for portraits.