there is certainly some mechanical vignetting below f/16, but not more than you would get with any of the other lenses you have mentioned - they will all have mechanical vignetting at apertures larger than f/22. Most LF lenses require to be stopped down to about f/22 to be completely free from vignetting within the stated circle of coverage. At any rate, I would think you might just detect a slight falling off in illumination towards the edges with the lens focussed at infinity on a 4x5, but close up? I doubt it - you really wouldn't be using enough of the coverage to see much variation.