As someone who has lived here for one year now, I can honestly say that Boston and DC are on par with each other when it comes to getting wildly lost (although for both it's much worse in a car, since I abuse one way streets on the bike)
People from DC always bring up the letters and numbers crap, and I don't care, it's a completely counterintuitive and needlessly complicated system. I get lost anytime I have to go anywhere new. And the signage is horrible.