We just got back from Boardwalk and loved it! Rooms were spacious and simply beautiful! The main reason I liked BW is because it was a smaller hotel with less rooms, so that no matter where your room is your 'commute' to the bus stop, food/snacks/drinks, nightly entertainment, shops, lobby, pool, etc., was only a short walk.
Someone mentioned this before, but it's worth mentioning again. We had a 4th floor room with a garden view (I heard the rooms actually overlooking the boards can be loud) and had an absolutely PERFECT view of the Epcot fireworks, not only from our balcony but when sitting on the bed in the room!
My only complaint about BW was that we were on the dining plan and casual breakfast options were limited. Boardwalk Bakery has delicious food, but there are only so many pastries, bagels and egg sandwiches one can eat in a week. Unsure if BC/YC has more options.