Standard and on-camera product images are also available.
There are many comparisons that can be made with these results, but ... no other lens provides the 20mm f/1.4 equivalent. Here are two comparisons to get you started:
Sigma 20mm f/1.4 Art vs. Canon 24mm f/1.4L II Lens
Sigma 20mm f/1.4 Art vs. Nikon 24mm f/1.4G AF-S Lens (different camera formats)