We like them both, but HHI is our definite preference! Why? HHI is a vacation destination in itself, so there are tons of great restaurants, concerts for kids, golf, mini-golf, bike trails, etc. when at HHI, we totally enjoy the resort, but also enjoy all the extra HHI fun too. We usually send the day going ack and forth between the beach house and the Big Dipper pool... Then out for a nice dinner or call in for pizza if there are evening resort activities.
We found that VB offered fewer activities for our school aged kids, and that the pool activity staff seemed to be going through the motions without a lot of enthusiasm (although one can't base a vacation decision on a few CM's may be having a bad week). And didn't like the fact that bike rental was by the hour/ day instead of length of stay. We also felt the restaurant was pricey, but no pricier than other Disney restaurants--- just fewer off-site options nearby, so we noticed it more.
However, VB had the turtle nests and snorkeling lessons....and mini-golf on site.