I just recently came back from my honeymoon, and stayed at the Vistana Villages and at Boardwalk Villas in Orlando. My impression is that the Starwood properties are bigger but nicely decorated. It was nice to come home from a long day in the park and relax. We stayed in the new section in VV, the Keys area, and we found it to be pretty quiet and relaxing.
The Boardwalk Villas is great in its theming. I thought the rooms are a little smaller than at Vistana Villages, but the Disney touch is incomparable. Plus, the advantage of not having to drive a car to the parks is great. One day we went to Epcot, and was able to go back to the room for an afternoon nap. Then we were able to go back to the park, and that day Epcot had Extra Magic Hours and we stayed at the park until 11 PM. These are the extras that make DVC unique.
My plan is to continue using both in alternate years, since I own at both. SVO will always allow me to stay at a level of luxury and comfort that we have come to expect. The flexibility of the DVC plan allows so many more possibilities. My plan for next year is to use my DVC points to go on an Alaska cruise!