we've found their prices the lowest for rental IN orlando airport (MCO), using discount codes of course. you can sign up at their web-site for "fast lane" - a seperate line for faster check-in (free).
alamo may be a few $'s less, but they are off-site (you need to take a van to get to them), and we've had rather poor experiences with them (2-4 hour waits).
if you're looking at orlando, mousesavers.com norm has the "codes".
(btw, we found both co's pushy with the "upgrades" - we just repeat "no thank you" a few times

)
laurie s