Might be true, but i find Make it Rain a better harasser, since it also applies a slow effect, which gives you more auto attacks, and helps your team catching up.
Also i find the Life Steal and ArP (if against heavy armors) more important than Infinity.

Edit: I just figured out that i didnt take Double up before 10+ which is a mistake :)

Thanks for commenting.

hey bud, im not going to rate u yet but how come u max double up last? its an amazing tool to nuke and harass and less mana then ur aoe?? also dont u think maybe infinity u getting is to late and more useless as 1 of ur first items?:)+0 atm