I am ruling out any hardware issues, since some server responses work perfectly at the same time others do not.
Example of things that work as intended:
Skill gains, chats, global spam, healing ticks, damage done to you
Things that do not work as intended: (keep in mind the other things work fine at the same time these do not)
Shots fired, item swapping, auto-fire working correctly, crafting /auction page load issues.
Ill post this quick and dirty stream again since it highlights this issue exactly:
I am leaning toward bad routing of packets on the server, making UDP pass, and TCP fail. I am also leaning toward a localized server farm, where the international pipelines coming in go to a different server than the local traffic...which would explain so many people near the servers not having issues at all.
I am also assuming that MA did the stupid...and gave the servers to some other company to run. Ive seen some of the tricks these places use to keep failing gear cycled with good gear to limit exposure to issues, and save every penny they can.