Personally I prefer a normal tent, since you have more space, and it doesn't have a suspension that moves around when you turn over.
The only times I'd use a rooftop tent would be:
When travelling far, and packing up camp on a daily or almost daily basis (ease of use).
Where there are many wild animals (e.g. lions).
With my normal tent, I can stand, walk around and fit a double bed blow up matress, little fridge, etc, as well as sit in comfortably when the weather is bad.