I suggest you look at online photos of both pools.
Stormalong Bay at Yacht & Beach Club generally is considered the best hotel pool. But with that said, we've encountered long lines to get onto the pool deck, problems finding a chair, and difficulty keeping track of younger children due to the layout of Stormalong Bay. With one child, the pool should be OK if you go early (e.g. 11 AM) or late (e.g. 6 pm) in October.
The Boardwalk Inn's pool is much more manageable. Per was @mstr425 wrote, the BWI's water slide is not only better than the Y&BC's, I consider it to be the best hotel water slide at WDW.
The Boardwalk Inn is an easier walk to Disney's Hollywood Studios. If you are planning to spend a lot of tine at DHS, the Boardwalk Inn cannot be beat.
Both the Yacht Club and Boardwalk are about the same walking distance to Epcot.
The Boardwalk (in front of the Boardwalk Inn) is fully accessible to anyone staying at any Disney hotel. If you are staying at the Yacht Club, it's a short walk or boat ride to the Boardwalk. The point is, this should not be a determining factor when deciding between the two.
A small food court was added to the Yacht Club in recent years. Before this, perhaps the biggest complaint about the Yacht Club was its lack of a food court.
The Boardwalk Inn's food court (called the Boardwalk Bakery) is only accessible from the Boardwalk. This means that you have to walk outside to get to it. It's great on a lovely day (and October weather should be pretty good) but terrible when it's raining.