I just returned from a week at HHI and went to VB last summer for a week. Both were great. I'm voting for VB due to the ease of getting to the beach. We are beach people and you have to drive or ride bikes over to the beach at HHI. Every afternoon when we arrived at the HHI beach area there was no parking. There is a shuttle that runs every 30 minutes but I was alone with the 2 kids and this was a hassle to haul all our beach gear and sit around waiting for the shuttle. It was so nice just to walk out to the beach at VB last summer. And when the tired of the beach a quick walk back to the pool or your room.
Staff at both are wonderful. Lots of activities for the kids at both places. Some of the activities seemd pretty similar at both; crafts, unbirthday party and Kids Nite Out. There seemed to be a difference in the structure of the Kids Nite out between the two places, however. They had Kids Nite out Monday, Wednesday and Saturday when we were at HHI recently. The Monday and Saturday were the exact same. Pizza in the community center and then board the shuttle to the local theater to watch Toy Story 3. On Wednesday the kids did something around the resort. At VB when they went to Kids Nite out it had more activities for the kids like crafts and games and each night was different. Forget if it was offered 3 nights or 4. I don't think it was each night, though.
Can't go wrong at either place. We all enjoyed both. My preference, due to the ease of getting to the beach is VB.