All of the above.
It depends on what kind of person you are and how you handle lines/waiting, etc. For example, if you arrive really early, like 10:30am...you will likely be one of the first people on the ship, however, you will have to sit and wait in the terminal for a long time. If you arrive later, say 1:30, you will like join a very long line that will trudge along very slowly, but there won't be much sitting and waiting...just standing and waiting!
This has been my experience. I personally like to arrive as early as possible at the port and get to the buffet on the ship early, because, after about 2:00 or so, it is jam packed. Of course, this all depends on many other factors beyond your control, so just go with the flow, and don't get upset.