Any views on this one?

It seems the main choices are aluminium, stainless steel and brass. As
far as I can see, aluminium needs the least maintenance. Is all
aluminium anodised or does this need to be specified? I liked the
idea of polycarbonate but I can only find one supplier, based in the
US.

It's for a common entry door so countering the lack of commonsense on
the part of my neighbours is more important than appearance.