My brothers and I (A family of gamers) got together one weekend for a 4 man dungeon. I was unable to dodge any aoe with my older laptop. Sitting side by side, we noticed that my cast bar would show up slightly after theirs and would finish casting after theirs were already casted. After 45 minutes of deaths, I switched to a newer up to date computer and the problem with the aoe-lag was solved. We also tested this on an older gaming pc we built 5 years ago in WoW's day and it was also having the same problem with all settings set to minimum.

Whether or not we are all affected to some degree I don't know,the 100-300ms. The only way to actually test this is to have multiple same top notch computers test for the delay I guess and then for lesser computers and so forth. Testing it for yourself will just give you results based on your system I feel. Sitting side by side with my brothers clearly shows an older pc performing poorly, especially my laptop for aoe.