This was my first cruise and my boyfriend's second. I found reviews that I read very helpful, so wanted to give my opinion for future cruisers.
Embarkation is Miami went very smoothly due to the fact that we arrived at the port around 11:00 AM. It was an easy cab trip from the airport of about 10 minutes and it only cost $24. There was some hold up when our taxi arrived at the port, being directed by the traffic officers there, so that took a few minutes, but I am glad we did it that way rather than wait for the Carnival group bus transfer. We left our large bags outside the port with someone from Carnival. They threw them on the big pile and we prayed we would see them again inside!
Once inside, the line was pretty short. Again, I think arriving early was key. Had we arrived at noon instead of 11:00, I think we would have waited 3 times longer in line.