I was told by the CM when we reserved that Ft W only has one six seat golf cart. It is slightly more expensive (I think I was quoted $67 and change with tax), but is often available for individual days. Since there is only one, it can be hard to reserve for your entire stay.
We chose to reserve it just for one day when we wouldn't be in the parks on our trip this year (we've never rented one in the past). Since we leave in less than 24 hours, I'll be able to tell you more about how it worked out for our family of six in a couple of weeks.