Kathyclownfish,
The advantage to curbside check-in is not having to lug your bags to the check-in counter and wait 30 minutes to an hour, depending on crowds, to check your bags. We always check our bags at the curb and then just check in down at the gate. It's a huge timesaver. Just one precaution, make sure when the Skycap tags your luggage that it says "MCO," the airport code for Orlando. Actually, you should always check to make sure your bags are tagged correctly, whether you use curbside or counter check-in. My very first trip to WDW, I saw my luggage going down the conveyor belt with a tag for Fort Lauderdale instead of Orlando. I started yelling and, thank God, they were able to grab my bags off the conveyor and re-tag them.