The BC is more popular than the Yacht Club and fills up a lot sooner. But keep checking for a cancellation, especially after the 30 day paid in full date.
The Yacht Club is very nice, too. The access to Storm Along Bay is much closer from the Yacht Club than it is from the BC. And you are closer to the boat and the walk to DHS. All of the Yacht Club rooms, except for one club level room, have full balconies while only 50% of the BC have them. And the park buses pick up at the YC first, which is a really good plus.