The Rodenstock f4.5 Grandagons are truly outstanding lenses according to their MTFs, with the advantage of a 1 stop larger opening. They are also excellent in other parameters such as distortion, etc. Focusing wide angles specially the very wide ones is considered cumpersome by several experienced photographers I know. The one stop greater aperture should facilitate focusing. Schneider Super angulons are also excellent lenses, and according to their MTFs about equal in performance to the Rodenstocks. I use the Schneider SAs with excellent results. You would be happy with either but I lean to the Rodenstocks because of their larger aperture. The Schneider SA XL lenses are very marginally better technically than the SA near equivalents, and have slightly greater image circles, but in 72mm and up sizes they require monster filters, 95mm, for the 75mm and 90mm; for landscapes that makes them not very practical. Nikkor also has F4,5 wide angles and one great landscape photographer I know uses the 75mm. Because Nikkor publishes no performance data I am unable to compare and I am personally more confortable knowing what I buy. I have not used the Grandagons but would like to replace my Schneider F5,6's with them. I would buy them without hesitation.