i think the only way to answe that is by asking yourslef what you want to do with the car.
if ure going on track or like racing people at lights (which i might add is just silly lol) then you might notice a slight decrease.
If u just drive around daily in it and open it up but are not bothered about .2 of a second then go get em
For me its looks not out and out performance. Although im still endecided.