I've stayed at both, and had a great time both times. You can't really go wrong.
Price being equal, I'd prefer the Yacht Club over the Cabins, for the pool, for the proximity to Epcot and DHS, and for the dining options around Yacht/Beach/Boardwalk/Swolphin. If my trip is going to be focused on those parks, and I'm going to eat at Disney restaurants, that's my pick. Whether that's worth the extra $600 is up to you!
I assume that the Chip-and-Dale Singalong and a lot of the other Ft. Wilderness activities are suspended right now, which really limits the appeal to me. Dining options at Ft. Wilderness are pretty limited, but you do have a full kitchen, and you can get to the MK-area resorts without too much hassle.
From the Cabins, would you rent a car? If not, it makes it quite a bit more painful to get to any of the other resorts since you have to travel to the bus stop first, which means either taking an internal bus or giving back most of your cost savings to rent a golf cart.
It's a trek from the cabins to the boat launch, but once you're there it's a lovely boat ride to MK.