It's important for us to realize that many agents have a work pattern of piling up queries then spending a few days grinding through a lot of them at once. It's not like they don't have plenty of other demands on their time!
Since we usually don't know what their schedules are, those of us who query right after a session may have to wait a long time for a response. Those who query right before or during a session might get a quick response.
So quick or slow responses should not generate an assumption that an agent is quick or slow all the time, or that some writers are getting special treatment while others get the runaround.