i checked both places information. Ho Coc is one of the top beach in Vietnam. All pics looks pretty. I realized that Vung Tau is crowded, and maybe dirty. But It has many great local foods. In Asian, we have an old saying that the most delicious/tradition foods are located in small alley or from the restaurant which even look not very clean. Foods are part of cultural, since we will have plenty of time to see beach in another two places, I would love to go to Vung Tao. I found an article to talk about 10 MUST – Eat Food in Vung Tau. Here is the link: https://www.justgola.com/blog/10-must-eat-food-in-vung-tau_1-157. But if we already plan to eat enough local foods ahead, then Ho Coc will be a great option too.