ISP: Time Warner Cable
Location: New York City, USA
When does it occur: all the time, but most pronounced during peak hours

I get routine, almost constant .5 - 1 second lag spikes, especially in crowded areas. Ping test reveals 2-4% packet loss to the server address (199.91.189.44), and PathPing shows this packet loss at end of the connection route.

These delays cause very frequent "stuttering" in terms of the movement of NPCs/players, and delays in casting spells, speaking to NPCs, and mechanics being shown on the screen (red zones). All of this contributes to a less than ideal and somewhat frustrating gameplay.