I have used both and have been pleased. Just make sure you are signed up for the Dollar Fastlane program. You still have to go to the counter, but they have a separate line for you. I have always been the only person in that line and gotten the next available agent (even when the regular line wrapped around many times). Yes, I got some nasty looks from the other customers, but they too could have signed up for Fastlane. There is no hassle at all. With Dollar you get the type of car you reserve, you do not have the "chance" of getting something special (i.e., van, convertible, etc.) as you do with National Emerald Aisle.