The Sheraton Vistana Resort is closer to the Disney parks while the Sheraton Vistana Villages is closer to the SeaWorld parks. That said, they are still in pretty decent proximity to each other, within just a few miles.
We own at the Resort and love it there!
This thread is a great resource for those looking to stay at SVR:
http://www.disboards.com/showthread.php?t=3148502
The majority of the resort is a series of low-rise, 2 or 3 storey buildings (with a few exceptions), and so the amenities are scattered throughout the property. No matter which section you are assigned to, you'll be close to a pool, playground, etc.
The grounds at SVR are gorgeous. The resort offers 7 pools (two with waterfalls, one with a slide, one that shows poolside movies throughout the week, one with splash fountains, 2 with in-water volleyball nets....but no lazy rivers like at WBC), 6 outdoor hot tubs, sand volleyball courts, basketball courts, multiple playgrounds, mini golf, tennis courts, and a whole host of daily scheduled activities from a farmers market to pool parties to bingo and wine tasting. Location is excellent...just around the corner from DTD.
The rooms were redone right down to the studs a few years back, and they are GORGEOUS and huge. Granite countertops, ceramic tile, really nice finishings. Most 2-bedroom units are 1200+ square feet. Each 2 bedroom unit (and some of the 1-beds) have a screened in balcony or patio. Each 2-bedroom has a washer and dryer as well as a jacuzzi tub in the master bath.
All sections except for Courts and Falls have one king bed in the master bedroom and 2 double beds in the 2nd bedroom, with a queen size pull-out in the living room. Courts and Falls have 2 singles in the 2nd bedroom.
The Villages offers a pirate themed pool that is good for the younger visitors, and I don't believe the property is so large and spread out as SVR. Those may be considerations you wish to keep in mind.