The most important thing for me is color rendering! Absolutely natural and combined with its excellent sharpness, the result is simply impressive!
The AF is extremely fast and completely silent!!
Its weight is very small compared to its size and the focus and zoom rings are very convenient in their positions. What I would like to characterize it as flawless and in terms of build quality would be for the zoom ring to rotate smoother, more velvety, without feeling any minimal internal friction. Of course, I don't have such expectations from a lens that changes its size during zooming, moving a large portion of the lens in and out, which makes construction and rotation feel less smooth.
Compared to the RF 24-105 4L, the EF 70-200 4L, and the EF 50 macro f2.5, I consider it to have clearly the best color rendering and sharpness!!