What exactly is the Marriott Vacation Club? Is it like a timeshare type thing, or is it a genuine club in which you get membership to the Marriott? I couldn't really tell on their website.
Personally I would head to the Laguna side, particularly the Dusit. We've just come back from the Marriott and it was miles from anywhere, and packed, making it hard to tae the kids swimming or to breakfast.
The Marriott Vacation Club is a timeshare type thing, and offers have been floating around that if you agree to sit in to a 60 minutes sales pitch (when you arrive), they will give you a free 3 nights stay. I received it in my email about a year ago, but deleted it because I didn't have any vacation plans at that time.