As a first time cruiser with my husband, we had a mostly positive experience with the Star Princess.
Check-in
Yes, there were lines, but not horrible. We arrived by noon as we figured let's just get started. First step - drop off luggage, go to enter line to get to security, up the escalators, go through security, go into another line to get cruise cards, from there, go enter into a line to get on the boat. Once on the boat - smile - time for a photo. This process took about an hour, lines were always moving (think Disney with the creative line development). Enter elevator, go to your floor, see room, and off to get lunch. For lunch, we went straight to the buffet, we didn't see that pizza and burgers were available if we would've turned right vs. left on the deck.
A519 - midships, quiet, balcony looked over on others, but no one looked over on us.