Phantom Dancer does not work?

12% damage reduction from enemy champions that you last hit

Does anybody feel any difference with and without it? For me its very very hard to tell if this does something or it doesn't

I think this % PERCENT damage reduction is a tank stat not squishy carry stat. Its so hard to tell any difference. Probably on tanks like Alistar would be way better than any squishy carry. I really want to build it but honestly it doesn't make my games any better