Choosing your portrait lens is not a trivial thing. most good portrait lenses are not cheap, and they will probably serve you for a long time. Preferences may depend on budget, size, focal length, aperture and any other number of factors.
Photographer Manny Ortiz has a quick video up comparing two fo the more Sony popular portrait lenses: The 85mm 1.4 GM and the 70-200mm 2.8 GM. While this is not a pixel peeping kind of review (frankly they are both really nice lenses), it sheds some light on how each one performs and how they feel in the real world.