We've never taken the ferry on the way to Florida, (we fly to WDW) but have taken it several times to Delaware coastal destinations. It's a great ride, as is the Chesapeake Bay Bridge Tunnel, but it will add quite a bit of time to your ride. Depending on the ages of your group, and the length of time you have allowed for travel, you will need to weigh the options. And also note that if you are leaving on Saturday, the Parkway en route to the ferry can get quite crowded near the beaches later in the morning. Be sure you are on that stretch of road EARLY. If you are, then I wouldn't think you'd need a reservation for the ferry.