I am generally a big fan of Dollar.
Still, 2 trips ago we had "Fast Lane" and it wasn't so "fast". They messed up our reservations so my wife had to wait in the queue after all.
Always pays to call the actual rental location a few hours in advance (or from cell as one walks down the terminal) and "check".
Folks are human and computers are unforgiving.
Have to say the return/location were terrific. I usually buy the tank of gas and not worry if I paid $10 too much for the 5 gallons still left in the car. It's just faster that way.
As long as their rate is competitive, they are always my first choice.
Warning: Automobile rental companies are squeezed so much by price competition that they underprice the daily/weekly rates and aggressively try to make-up by squeezing in the extras.
One example at Dollar is that they almost always put the squeeze on for the "upsell". If one rents an economy car, they offer to "put you in a midsize for just $7 more a day" . . .
This can work, if you really want a midsize and are prepared to "bargain" a bit. Book an economy and negotiate. Also, it can backfire if they don't have any availability.
And always, always check with your car insurance agent and credit card provider to determine if you really need "insurance". Those fees (equivalent to $2,000/year for automobile insurance) are not good deals.
Good luck!