The Boardwalk is one of my favorites!! I've stayed at WL and, while I think it is beautiful and we still go on almost every trip to eat at Artist Point, we will probably never stay there again. The rooms were too small for us and I felt quite isolated with only a boat to MK and bus everywhere else.
BWI is fantastic! You will have a bigger room, can walk to both EP and DHS, have tons of dining options, entertainment on the Boardwalk every night. Imagine going to Illuminations or Osbourne Lights and simply walking back to your resort! I also love the decor of Boardwalk. So many beautiful, interesting objects in the lobby. Great places to just sit and enjoy the Boardwalk, too. If you google Boardwalk Inn WDW Christmas, you'll see a lot of links to pictures and even You Tube videos of how it's decorated at Christmas. They usually even have a gingerbread house where you can buy treats.
We've stayed in a few different categories at BWI from standard to concierge to villas at BWV and we've never been disappointed. And if you are getting the room at the same rate that you would get for WL, that's a great upgrade!!
As far as EP resorts, BC and BWI tie for first for me, followed by YC and then Swan/Dolphin. The atmosphere and proximity to EP and DHS just can't be beat!