I have driven old and new Fortuner (not in Pakistan) both with 2.7 litre petrol engine.
Certainly with the updated chassis new Fortuner is comfortable compared with previous gen. Fortuner. However both are awful compared to a sedan.
As you asked, yes 2.7 litre petrol engine is sluggish & slow. Body weight to bhp/torque ratio is at lower end. But it should be fine within city (as you wont be driving up the hills). Acceleration is also an issue, but its understandable as its an rigid SUV.