Image quality test results from the EOS 5Ds R and 7D Mark II have been added to the Sigma 28mm f/1.4 DG HSM Art Lens page.
This lens is competing strongly against the best. Here are some comparisons to get you started.
Sigma 28mm f/1.4 Art Lens compared to Canon 24mm f/1.4L II Lens
Sigma 28mm f/1.4 Art Lens compared to Canon 35mm f/1.4L II Lens
Sigma 28mm f/1.4 compared to 24mm f/1.4 Art Lens
Sigma 28mm f/1.4 compared to 35mm f/1.4 Art Lens
Sigma 28mm f/1.4 Art Lens compared to Zeiss 28mm f/1.4 Otus Lens
The Sigma 28mm f/1.4 DG HSM Art Lens is in stock at B&H | Amazon | Adorama | WEX
Rent the Sigma 28mm f/1.4 DG HSM Art Lens from Lensrentals.