Agree with Doug, at least on the DC/MD side. Have not fished from the VA side so it may be different.
From a boat full sink no question. But, from the rocks I've found it difficult to find a spot where a full sink does not drape over the rocks before the deeper channel.
I keep a full sink with me, but rarely use it.
Best success and least frustration has been with either a floating line with an 8-15 foot sink tip or an intermediate with a sink 3 tip. Slower sink especially in very slow current gives you time to work the fly.
I find alot of this, frankly, is dictated by when you fish and how many people are there.