Enjoy the tour, its fun and low-pressure for being a timeshare pitch. They used to give out gift cards, but lately they've only been giving Fast passes to compensate for the time you lose in the parks (I think 2 per person?), which is a nice gesture. They have a room where your kids can play video games and its a nice break in air conditioning where they give you some drinks, cookies. During busy times they do make a lot of appointments so if you know you want a particular time slot (eg. right after a lunch reservation, etc), it might not be the worst idea to make a reservation for the tour before your trip - if you want to do that, I can give you my guide's e-mail address or phone number, she's pretty nice, or you can just call the DVC desk. If time slot doesn't matter to you then just sign up at a kiosk.
When we went the first time it took a little over an hour for the tour. At the time they were only selling AKV so we declined. When we heard they were selling VGC we built time into our trip specifically to make the purchase, and that tour ended up taking over 3.5 hours from beginning to contract signing (felt bad for the DNeph, we'd only planned on it taking 2 hours). They gave us about half a dozen FPs each though which was handy the next day.
If you're seriously thinking about purchasing eventually, though, before you buy look into the resale market, particularly one of the board sponsors is the Timeshare Store. Exact same product, a lot less $. The few options one can't use the points for are things that are not cost effective anyways. And read lots on the DVC Purchasing board. Its a great system, and we don't regret our purchase, but there are a few things I wish I'd known ahead of time (mostly smaller contracts are better than larger ones in case you want to sell down the road and you can ask for any UY you like).
On the other hand, on the off chance that you do decide to buy directly from Disney, you could always say I referred you then we could both get extra gift cards.
