DxOMark just released the results of the FE 16-35/4 and it just squeezes in as the best 16-35/4 on the market (by a fraction, but a significant fraction!): At 16mm: Looks about dead even, though the Nikon seems to be fighting a slight field curvature At 24mm: Starting to pull ahead of the Canon version... which mind you is tested on a much lower resolution 5dIII At 28mm: Well the Canon isn't looking so hot. At 35mm: Surprisingly, the Canon comes back into its own, but the Nikon is awful. However, Canon is poorer than the others in its mid-zoom, and Nikon at tele. So for consistency at every focal length, Sony does amazingly well. And in a smaller package to boot.