Diesel cars dont rev as much as petrol so you dont use "top end of the rev range". As a result I find that in my car, the mid range performance is improved with premium fuels ie lower down the rev range for a diesel. Therefore you do
notice it every day as you only need to squeeze the throttle and feel the response straight away.
In a petrol, then yes I would imagine you would need to rag it to feel the benefit from putting in premium stuff.