User blog comment:Just loves to play/Bloodthirster/@comment-5333760-20130618153939

building BT early gives you


 * damage and sustain advantage against lane opponent


 * AD spike

while brutalizer gives


 * cdr


 * armor pen

both are great stats but since BT is more expensive and you can have sustain with pots... but i generally dont buy pots (they're waste of gold) so i really rush vamp scepter on my ADs... i depends on whether you are a spam type of person(brutalizer) or an AA type(BT)