I only stayed one night here at the Imperial. It is a huge hotel with beautiful grounds and swimming pools, and right across from the beach. There were lots of families with children around. I was here for business so did not utilize all of the facilities. The breakfast in the morning was also excellent. There is an attached small shopping plaza next to the hotel. There is a pedestrian overpass to get to the beach, so use it - don't try to cross the street (although traffic in Vung Tau is not too bad).
I did not care too much for the room however despite having a balcony overlooking the beach. The decor in the room (old colonial style) was just not my taste. My room had a separate living area with a small kitchen, but it was just oddly laid out. The bathroom was just so small.
Overall, the Imperial is definitely worth a stay as it is one of the more upscale hotels in Vung Tau, especially if you want to be on the beach. Please make sure to watch the warning flags on the beach for strong waves and undercurrents. On the day of my visit, warning flags were up for most of the day.