Dollar's MO is to charge the normal base rate (same as what a normal non-one-way rental would go for) and add a drop fee. Hertz's MO is to charge a higher daily rate for one-ways but no drop fee. Hertz typically has the price advantage for short rentals, and Dollar typically has the price advantage for longer rentals. (That is, Hertz may charge $50 per day for 18 days for a total of $900, whereas Dollar may charge $20 per day x 18 days + $300 = $660.) This would explain why fsexman said that Dollar is significantly cheaper. (fsexman, do make sure you are seeing the drop fee as Mrp Alert suggested, though, before being sure of your total price.)

There's nothing to be afraid of when renting from Dollar--many of us have rented from Dollar countless times without any problems. As a company targeting the value market and usually with lower rates, the only thing that might happen is they might not be as forgiving if you make a mistake--in other words, if you bring the car back a couple of hours late, they might not waive the late fees, and they may be a bit more picky about damages (so do your initial inspection when picking the car up very carefully--I've heard that Hertz has no problem just not charging people for bumpers when they crack it when backing up into a deck, and I simply cannot fathom why...a scratch, maybe, but a cracked back bumper?)--but that's it. They're not going to actively rip you off (i.e. falsify damage just to charge you for it). So just make sure you follow the letter of the rental agreement and you have nothing to worry about. (Also, the SAN store is corporate, and most problems happen at franchised locations with greedy owners. Corporate stores are more or less uniformly bland--neither stellar nor bad.)

A note for any car rental company, not just Dollar: you should always look at what you're signing to ensure you don't end up with a coverage option or upgrade charge you don't want. A well-trained agent should fully disclose your charges, but admittedly, not all agents are as thorough as they should be and will just circle fifteen different spots and tell you to initial them all. (I've had this happen at many rental companies, like Alamo, not just Dollar.) I say this not because the Dollar agent is trying to rip you off and add something without your knowledge but rather because in a sales transaction, it is always easy to misunderstand the other person and make an incorrect assumption (i.e. the customer asking for a bigger car but wanting it for free and the agent assuming the customer is willing to pay for it). You may find the sales agents a little more eager to sell you something than at Hertz, since Dollar's razor-thin (and sometimes negative) margins on the much lower base rates mean that the sales often are the only thing keeping the company afloat. Reading your contract (both the charges and any special notes on the front page; you can skip the fine print on the back, as it's the same at every rental company) before signing it will solve nearly every problem you may ever encounter. The one fine-print T&C that differentiates Dollar (at this point, corporate stores only) from other major companies specifies some potential extra fees for returning early or late; call and ask ahead or ask the sales agent at check-in for details.

You can replicate some of the experience of your #1 Club Gold membership by joining the free Dollar Express program. If the location does it right, your contract should be pre-printed, leaving you simply to sign and go. It's not as thorough of a program as #1 Club Gold--you still have to sign rental agreements and your car will probably not be in any super-elite front-row parking stall--but it does eliminate much of the hassle of renting a car (and hey, it's free, unlike #1CG, though yes, I do know you can get it free with myriad promotions).

As to the "Lock Low and Go," as you've probably guessed, it can be anything. It's difficult to predict, but you might be able to draw some conclusions from the Lock Low and Go thread or the related Consolidated Wild Car Thread in the Thrifty forum. (Dollar and Thrifty are owned by the same parent company, and in San Diego, they are right across the street from each other and are both corporate stores, meaning their behind-the-scenes operations are consolidated and they share a fleet. Wild Cars at Thrifty should be similar to LL&Gs at Dollar.)

One note: the virtually identical Thrifty Blue Chip program comes with one extra benefit: a satisfaction guarantee, which gives you a free day, no questions asked, if you are not fully satisfied with your experience. All other things (rate, location, etc.) being equal, if you have the option to rent with Dollar or Thrifty, choose Thrifty (and reserve with your Blue Chip number) for that one tiny extra measure of protection.