I ve been using the d800 for about 6 years professionally (fashion mostly). Lately I am not happy about its auto focus capabilities for shallow depth of field, plus want to have decent video capabilities. Currently have nice lenses like; Nikon 24-70 2.8 sigma 35mm art Nikon 85 1.8g thinking about buying a mirrorless device, do you think, it would be a big improvement from d800 to Sony a7r iii? (with tamron 28-75mm 2.8 + sigma 85mm 1.4g art) I am more towards to a7r iii rather than z7 because of the eye focus, but not sure about the tamron lense and change the complete set. any ideas will be welcomed. thanks!!