DVC Mike makes some excellent points. We do own at both resorts so we see the advantages of ownership for each.
For late August, I think you will be able to book either one of the resorts at the 7 month mark. So general availability won't be your biggest concern.
As indicated, VWL is very small so even though you plan on late August vacations now, at some point your vacation patterns may change. We always go in the summer because of the children and school, but last year we went during Christmas to VWL. Just stunning, and very hard to book without home resort advantage.
On the other hand, we had a trip to BWV a month ago and were able to stay in a Standard View room for significantly fewer points than the regular room point rates (which are the same as VWL). So we enjoyed the convenience and amenities of BWV for far fewer points.
Likewise, being a BWV owner gives you a much better shot at Boardwalk View rooms which are highly desired by many.
I can see why you're torn. If you can split your point total and buy at each place, that would be ideal. That's what we do and we bank one contract and borrow from the other and alternate our stays with the ability to still book an entire trip at the 11 month window.
I think if I were making the hard decision between the two (and liked both equally), I'd probably lean towards BWV. There are more home resort advantages to being an owner there, and you would most likely be able to book VWL in late August fairly regularly at the 7 month window.
Good luck with your decision...isn't it great to choose between two wonderful options?
