They are supposed to be more aggressive versions of the SS meant for heavy beards. I've been wanting to try one but havent seen one around at the antique shops.
I found the regular ‘50s SS to be quit a mild shaver. I’ve wondered if the red tip is considered more aggressive because of blade angle/clearance, or simply because it’s heavier and the added weight puts more pressure on the face while shaving. Questions, always questions…
I use the red tip more than any other DE razor. My fatboys, slims, and super adjustables have been gathering a lot of dust for the last few months.