Follow Kris' suggestion and just go for the shortest line! If all your info is already filled in, the check-in process should be smooth. Princess always seems to be the most organized when it comes to check-in!
I will have to say the record goes to Celebrity this spring for the "lei'd" cruise. I was worried because I hadn't sailed with them before and thought it might take me a long time. Everyone was in the past passenger lines, I walked in, said I wasn't a previous passenger and I was done in 5 minutes flat!
Enjoy your cruise! Susie