i have some old German made Wera square drivers, but rarely ever come across Robertson screws, think I've used one once, seemed ok, i guess if i used the often id notice a difference.
i didn't realize that Robertson made there own drivers etc, though or that they were still around (just googled them) I know the story about the patent theft so its not really surprising thinking about it
If they get more common over here i might invest in some real Robertson ones, currently there only seemingly used as anti tamper screws, due to there rarity i guess
i know snap on has recently released a version the drivers (with the handles correctly colored for the different sizes) so maybe there gaining popularity outwith Canada?