First, I wish I read all the negative reviews before making my trip.
To be fair, this place probably deserves more than 1 star, but not by much. The plus side is you can pick your own car and the return is speedy (at least at 5am).
Now the nightmare part, like many others have said, there is a very long line when you pick up your car. What makes it worse is most people have to spend 10 minutes or more with the rental agent. You have to spend an hour or so just waiting in the line, wondering what's going on. When finally it is your turn, you will find out why. They will ask you irrelevant questions like where you stay then try to sell you everything possible based on your answers.
I will definitely NOT going back to this place. Budget, AVIS and Hertz all have very competitive rates in Vegas. Maybe 10-15 dollars more for a weekend rental but it will save you 1 hour of your vacation time and all the hassles. For those of you who still want to choose Dollar, please firmly say no to their sales pitches and do a favor to those who are behind you in the line. I found it amazing that many customers are still in a good chatty mood after 1-hour waiting.