Have a look at the attached picture. Left: A1 Super Adjustable at #5; Right: O4 Super Adjustable at #3. To me both blade gaps look (more or less) the same. This makes me wonder if the precision suggested by the Double-Edged Safety Razors Ranked by Aggressiveness wiki page isn't unrealistic. If there are such obvious differences between different incarnations of the same model, can we really say that (for example) setting #2 on a Super Adjustable corresponds to setting #1 on a Slim Adjustable, as the wiki page does?