Stayed at LM and Vinpearl recently and both are great.

Pick LM for the location since it is at City center. Vinpearl however is located farther out but Grab is so cheap that few dollars get you in the city. Also it is directly connected to a large mall.
The LM lounge is still above average for Asian hotels.
But Vinpearl has better view and the lounge is much bigger with better food and choices.