Have used both Dollar and Alamo recently, and found Dollar to be faster (although only slightly)at check-in and check-out. Found the rates for both to be similar for each class of car. Most recent experience (Dollar, at FLL airport), I found the lines at Dollar to be much shorter, with their bus dropping us right at the car, and their cars in good shape, and clean. Check-out took all of 30 seconds, and then quickly on the bus back to the terminal.

bj-21.