I never tried them until I got a pack with an Edwin Jagger DE89. I thought they were rubbish. I had been DE shaving for well over a decade and they caused more irritation than almost any other blade I've used.
I find Derby Extra blades lovely and smooth but they just don’t shave as closely as I want. I’ve tried to love them because I really enjoy shaving with them but I get annoyed at the lack of closeness. Maybe I should try them again and add an extra pass or two to my routine.
Some razors, and some blades, take more work to get the same final result.
True. I don't like the Jagger DE89 for that very reason.