Kilee, be careful with Westgate. All their resorts have had wildly varying reviews. Some people love their resorts and some have told horror stories.
Coachv, Vistana Resort is older, located about a mile+ from Downtown Disney, down the street from the Crossroads Shopping Center. Some sections are at least 15 years old, so more spacious and less luxurious than the newest sections. Cascades is newest, so request that section if you choose this resort. The resort is very spread out and large, with many pools and sports amenities from which to choose.
Vistana Villages is a brand new property by the same developer. This one is much smaller, with one main pool area (reportedly nice with a waterfall and zero-depth entry edge for the little ones) and fewer onsite amenities, no restaurants. The rooms are supposedly lovely.
Vistana Villages, Marriott Grande Vista and Hilton Grand Vacation Club are all located along the same stretch of South Int'l Drive - a good area with wide commuting roads and reasonably little traffic. Of the 3, VV is the smallest & closest to WDW (though only by a bit), MGV & HGVC are a bit more upscale with more pool and play opportunities and MGV has a golf course onsite. SkyAuction would never list MGV because it is associated with RCI resorts and MGV only trades via II, the other timeshare exchange company. HTH.