I can tell you from experience that studios seem to be the most difficult to book at BWV during the value season. I think a lot of adults without kids (such as my husband and myself) tend to go during that time because kids are in school and the points are so much lower. Standard view studios go VERY quickly at the BWV (for our trip coming up in January I called on the first day of my reservation to book and inquired about how fast they were going and by 9:30am around 3/4 of the standard view studios had been booked already... needless to say I called daily, and one day I forgot and didn't call until after noon and was told there were only 3 left! this is at exactly 11 months out day by day).
If you want to stay at the BWV, I would highly recommend buying points at the BWV... I haven't had a problem getting what i wanted there (though sometimes preferred view was necessary) when I booked within the 11 month window but within 7 months I have always had to stay at OKW.
Lisa