Sorry I didn't see your post before now. I use DOLLAR at LAS every month. I recommend, whether you are using them once or frequently, join the FAST LANE. Its completely free. Sign up at their web site.

With FAST LANE you bypass the counter and go directly out to the lot. Get your bags and get on the bus. When you arrive at the lot, you go to a desk and they have your contract pre-printed. Pick a car and you are gone. 95% of the time they are very efficient at LAS. Every now and then they are screwed up -- usually when I'm in a rush.

I have the option of using HERTZ, but I use DOLLAR because frequently the don't have the car you reserved and then I get a free upgrade. Reserve a FULL and you get a PACIFICA at a price that is about 50-70% of HERTZ, sometimes cheaper.

They are not HERTZ, but they are not too bad. The car you get for the money generally is worth the slightly less competent service.