Large Full frame (36 x 24 mm) sensor Large sensors provide shallower depth of field and a nice blurry background for your portrait shots.
Very Low Resolution Sensor: 10.9MP Sony FX6's 10.9MP sensor will not provide much room for cropping or large printing your portrait shots.
No Image Stabilization Lack of Image stabilization may result in blurry photos especially in long exposures and at long focal lengths