ME buses usually are full or close to it. If Disney is collecting your luggage, you'll go straight to the ME check-in desk. That line could be 10 minutes long or 45 minutes long, depending on # of folks arriving at that time. Then you go to the bus line based upon the resort you're staying at. Again, you might wait a short or long time. Bottom line - it's possible to check in to your resort 1 1/2 hrs after flight arrival.