We usually walk from the BCV to the DHS. It is really a very nice peaceful walk unless it is brutally hot, then we will take the boat. There is no question that it is quicker than waiting for and taking the boat.
We always walk home at night, as it is a nice, quick walk.
I agree it is about a 15 - 20 minute walk. I think the above map makes it look longer than it is. We actually take a left and pass the Swan and Dolphin and YC rather than going the whole length of the Boardwalk toward Epcot. Eiterh will work.
Have a Great Trip