GEEZ!!! Could you have made that anymore tough?!?!?
I am going to have to vote DL....mainly because I know *I* want to visit both sides of the country before the 50th is over, and plus 5 nights is the PERFECT amount of time for a DL/Southern California trip. (It's not quite enough for a WDW trip in my opinion.)
And I've ALWAYS wanted to stay at the DLH, but haven't got to yet.
So....if it was ME....I'd pick DL/DCA.
Oh, and P.S. I think you're right, that being in DL during the weekdays will save some of the crowds that you would face in WDW at that time. It's still crowded in the summer, but the weekdays are an improvement.