Decent. My only experience of a 4 series was when I had a 420i convertible as a hire car for the day and I was shocked at how slow it felt. It took ages to get going even at full throttle but I put this down to the fact it’s was carrying a couple of hundred kilos of folding roof.
Didnt matter really as convertibles are best enjoyed at slower speeds and they’re too low for me to drive everyday anyway.