Originally Posted by Morphinominal
It's a matter of two things, in my opinion, which one benefits the champion's play-style more?
For example, Lets take a look at two champions who, I believe, would benefit more from each.
Vayne: When Playing Vayne, her W allows her to deal true damage with every 3rd strike, so wouldn't it be essential for her to be able to attack faster to so that she can keep her silver bolt stacks active and potentially deal more damage. So I would prefer Phantom Dancer over Infinity Edge
Ashe: When Playing Ashe, she gains no additional bonuses to attacking more quickly (like Vayne with her W) So the priority would be to make sure that she's dealing more damage with each hit. therefore I would prefer an Infinity Edge over a Phantom dancer. ((this does not mean it's not a bad idea to build a zeal in the meantime)
Just my thoughts ^_^
I agree with this except the fact ashe does benefit from increased attack speed, from playing ashe quite a bit i feel that the difference between early kills and team kill wins is the ability to keep landing those perma slow Qs on, because ashe is decidedly weak early game, her best bet is to so down her opponent as much as possible to either grind chase a kill before tower or slow down a opponent enough for a ally to own
that being said, until ashe gets a Bloodthirster or IE she is almost a liability, i usually rush a zeal then get BF while deciding to go for bloodthirster or ie
just my thoughts though