We used the on-line check in. We gathered our luggage on a cart, went out to the garage, picked out a vehicle, loaded up, and gave our credit card at the kiosk at the exit from the garage. It went really smooth for us.
We did not, however, have any Alamo money, which may require you to use the counter (Is there any "small type" on it?). Why not call the Orlando location directly to find out? Here's the office location from the Alamo website:
Orlando Intl Arpt (MCOT71)
Orlando
Orlando International Airport
Orlando , FL 32827
US
Phone: (888)826-6893
(407)855-4170 ext:LOCAL
Fax: (407)850-9680
Hours: Sun-Sat: 12:00 am 11:59 pm