You can elect to leave the ship as soon as it is cleared (possibly as early as 7:30-8) but this would mean you would take your own luggage off the ship. This is good if you have your own car or have a car picking you up. If you take Disney transfers you are at the mercy of when they leave and how many stops they make. It's best to get on the earlier buses as I've heard the later buses may sit longer to fill up and then stop out more resorts meaning you could be on there a while if you are the last stop.
In the past, I have left the ship around 8-9 and taken the shuttle to Budget to retrieve my reserved car. From there we've been able to get directly over to our resort, check-in and be at the park of our choice before noon.