I have been an owner at OBBR for almost 20 years and from my experience, unless you own one of their 'fixed' weeks, they will not guarantee anything. You will have an opportunity to express your desires when you return your arrival information to them.

It is possible that there are different rules for exchanges than for owners but I have never heard of any. The biggest thing in your favor is the timing of your trip, low season vs. high season.

Either way, I believe you will enjoy your stay there.