A lot of it depends on when you will arrive on the day before. It's usually after 5:00pm by the time we land, so we stay at the Hyatt at the airport. It's more expensive, but very convenient, as it is right in the terminal. If you land earlier in the day, you might want to consider going over to the coast that day and staying near the port. Many people choose the Radisson in Cape Canaveral, which is only about 3 miles from the port.
I personally would not bother going over to the WDW resort if I landed in the afternoon on the day before the cruise. It's actually further from the port than the airport, and I don't feel that there would be enough time to actually do much of anything other than eat dinner and get some sleep. I can do that at the airport.
You'll get lots of differing opinions on this. That was mine....