There's really no comparison between the two. Disney Springs is a massive shopping, dining, and entertainment complex, and the Boardwalk is a resort with a few restaurants, a couple of shops, some entertainment and games, and a dance hall.
Don't get me wrong, the Boardwalk is a beautiful resort and a great place to hang out, walk, and get ice cream after visiting Epcot, and there are some really good restaurants there, but there's really no way to compare it to Disney Springs. They're completely different things.