Welcome to the forum Peter! The only thing I heard about the V8 PLus speaker is that it's okay but it sounds worse than a Model 3. You'll have to see it for yourself and let us know if its true.
From what I gathered, the VinFast Eco and Plus trims both use an 87.7-kWh battery. The Eco trim has 348 horsepower and 368 pound-feet of torque, while the Plus trim has 402 horsepower and 457 pound-feet of torque.