Sigma 24-70mm F2.8 DG DN Art Hands-on Review by DPreviewTV
The conclusion is that this lens is incredibly good value against the Sony GM lens. The only lens that can compete in terms of value-quality balance is the Tamron 28-75mm f/2.8 which is a lighter lens but not as wide as the Sigma.
Sigma 24-70mm FE lens at Amazon, BHphoto, Adorama, Calumet DE, FocusCamera. WexUK