I had quite a bit of fun in Syndicate today and yesterday.
If there are people in the server, the easiest way to find action is to fly around the ships. If you fly around your ships, you'll see the flak shooting at enemy planes when they are in range. Just look for the plane they are shooting at.
Or you can go to the enemy ships and the flak shoots at you so the enemy players know how to find you.
Joining the other players in the Ventrilo server, is a much more reliable way to find action tho.