I hit the DZ about once or twice a week for an hour or so (that's all I can stand). I typically just hunt rogues and take down landmarks. I find the DZ pretty full almost everytime I go in. Once you find a man hunt, you will see about 6 agents following. If it's a timid server, the 23 other players will end up being spread out thin so it will seem dead. However, if you go man hunt, you will find all of them pretty fast.