Yes I have noticed the hesitancy as well, as soon as I drove it really, and I can feel the change between the COD cutting in and out. Personally I will not be wasting my money on anything other than supermarket fuel. Nothing out there has ever convinced me these 'premium' fuels are anything more than a marketing ploy...
). Their prediction is that the turbo needs to be changed at least once during the life time of the car.