[crdb]

I've always wondered why there might be a difference for blades.

Creams and brushes, sure. If you have very soft, sensitive skin and soft straight sparse hair, you won't enjoy a hard brush and you won't need as thick a lather as someone with thick curly hair, so you might prefer a softer brush (less "backbone"). And some people might have adverse reactions to lanolin or find menthol irritating rather than refreshing.

But a blade's sole job is to cut hair, for which, presumably, the only quality required is sharpness, preferably retained for as long as possible. Aside from a less sharp blade being less of a pain on someone with softer and sparser hair, I can't see how blade experience would vary from person to person. What's your (or grandparent's) view?