The balance of the standard test results, including flare, distortion, vignetting and 7D II image quality, along with specs and measurements are now available on the Sigma 20mm f/1.4 DG HSM Art Lens page.
Go make some comparisons. I'll get you started with one that I find interesting.
B&H has the Sigma 20mm f/1.4 DG HSM Art Lens in stock.