I have been to both, and they are both a great experience. How can you go wrong!
I do favor SPAV for various reasons. Number 1 is Frank and how easy he makes everything. If you want to go to Santo Domingo, tell Frank. If you want to go to the water park, tell Frank. If you want to exchange money, tell Frank. Frank makes your trip entirely stress free and easy.
I enjoy the lineup and playing pool, having a movie night or any other activity where you are with all of the chicas. The beach is close and private, you can rent a table and chairs at the beach for about $5 or so per day.
Nice shops, restaurants and bars are close by if you choose to venture out of the resort.
It is a more relaxed feel than Boca Chica.
To me, the main reason to choose SPAV is Frank, he is truly a wonderful person.
Book your flight and enjoy!