I just bought this lens yesterday. Loving it so far! On a related note, I tried an admittedly non-scientific experiment and shot a building with my RF 10-20mm f4 at 14, 16, 18, and 20mm versus my RF 14-35mm f4 at the same focal lengths. I wasn't standing in *precisely* the same place, but I found that the 10-20mm images were less "angular" - that is, the walls weren't pyramid-shaped in the way the 14-35mm rendered them and they looked more natural as a result. Enjoy!