Just back from 2-2 Magic, we booked 1040am Radisson shuttle and even though it was running 10 minutes late we arrived at the port at 11am sharp, checked luggage, and finished check-in by 1130am, and the lines for check-in were not bad at all.
The line to board the ship was another story though, but still not bad. We dawdled a bit getting into the boarding line and it quickly snaked all the way through the cruise terminal by 12noon.
They started the boarding around 1220 I think and we were in the second wave of "embarkers" (they boarded the first large group of 100-200 people, then all of us remaining next in the line had to wait 5-10 minutes for our "second wave" of 100-200 to board). That was OK though, it was only 1245 then and my family headed straight for Deck 9 buffet to eat while I ran up to Palo for ressies. It worked out just fine.