The DTD hotels are a great low cost alternative to the high rates on site.
I've been inside the Hilton, the Courtyard by Marriott, the Grovesnor, and the Wyndham palace. I think the nicest one is the Wyndham. I would not consider the Grovesnor no matter what the price.
The best deal going is the Courtyard $20 special. Even Priceline can't beat that. The room you'll get will be almost the same size as a deluxe on site, but without the upgrades. It's your basic Marriott hotel room. If you need a hotel just to "sleep", you are sacrificing nothing. If you spend a lot of time in your room and you expect luxury, this hotel is not for you. I'd definitely pay $20 a night for this place but not $100. I'd rent a 3 bedroom vacation home for the same price instead.