Okay, in that case you will have full access to all of the WBC pools, lazy rivers, and other activities. The Grand is not "next to" WBC; it's really more right in the middle -- it completes the circle of buildings on one end of the lake. About the only difference is you'll have to pay for parking, I believe, in some form (either straight parking or a "resort fee.").
On the timeshare presentation, just be prepared for a low-pressure group meeting start followed by an individual session that will get progressively more high pressure as you go. They will also introduce at least one other "closer" to apply more pressure. Wyndham is a good system; just don't buy it from them!