Afraid I have failed all of you beautiful people here. When we arrived, we went directly to
Alamo (yes outside using our pick-up ticket) and I never passed by the Dollar or Thrifty desk to see if there was anybody manning it. I tried to look...but couldn't see them. I will say Alamo was great, we just went to the row, found a car, drove off and showed our electronic "ticket" at the gate to get it. Very smooth and easy.
Now...I have another trip next week. I have Thrifty and Alamo both reserved right now. Perhaps I will try Thrifty first to see what the situation is there? If it doesn't work out, I can always still use Alamo as my backup plan. We were very impressed also with the fact that the Alamo mid-size (Toyota Corolla) was in much better shape than our last few cars from Thrifty, and was also clearly recently cleaned (our last few Thrifty cars have not seemed very clean to us).
So I'll try to update again at the end of NEXT week if I try this!