I live in Brazil and I dont remember having any kind of lag issue.
Its pretty much amazing people in the US complaining about lag, since you guys are closer to servers than I.
I'm able to play every lvl 50 content with no lag, sometimes I even move a little bit late and can avoid AoE for a lenght of a step. For me that means that I'm perfectly (or close) syncd to server, no? Since we connect to NA servers as well.

I'm on a 100/50 optical fiber connection.

Sry for my poor english.