Need, I have been on the Pride a couple of years ago and it is a great ship but what really matters is the experience you will have on it.
When I went on the Pride it was with a small group from CFL now going with VTG and want to experience this ship with a larger singles group.
As for the Queen Mary I didn't notice any ghosts since I don't believe in them. It the living you have to worry about.
I will arrive in California 2 days before the cruise starts and stay one day after but I decided to stay on the QM so I will not have to pay for the shuttle to the port.