In terms of EPCOT distance, nothing is closer than BC. Although, when it comes to MGM, if you're at the BWV you can get to the "walkway to MGM" very easily from the villas side out by the luna park & quiet pools. I routinely got there at a brisk walk to the gates in 8 minutes. BWV to EPCOT is further--about 12-14 minutes.Both BC and BWV offer the huge benefit of being within walking distance of 2 parks. Which--if you don't mind walking is GREAT. I have very often chose to walk home from either Epcot or MGM after closing when DW and MIL,etc. would INSIST on waiting in horrendous lines for a boat.I'd even push one DS in a stroller as I walked.
..Also, I just found this on another site that, it might help you:
All times and distances were recorded on a pedometer, worn by the same person, walking at an average-to-brisk pace.
Boardwalk Inn Resort entrance to Swan and Dolphin Resort
5 mins - 0.2 miles
Epcot International Gateway to Epcot monorail station
15 mins - 0.53 miles
Swan and Dolphin Resort to Disney-MGM Studios entrance
18 mins - 0.83 miles
Swan and Dolphin Resort to Yacht and Beach Club Resort lighthouse area
7 mins - 0.28 miles
Swan and Dolphin Resort to Epcot International Gateway (via Yacht and Beach club)
12.5 mins - 0.52 miles
Swan and Dolphin Resort to Epcot International Gateway (via the Boardwalk)
11.5 mins - 0.49 miles
Yacht and Beach Club Resort to Epcot International Gateway
5.5 mins - 0.24 miles