Replay analyzesrs are the best for figuring out what exactly you are doing different than other people. When driving it might seem you are doing exactly what the WR holder is, but analyzers tell you that you aren't. And it's the little things that matter, getting on the throttle after a corner a few fractions of a second later means a lot more at the end of the straigth etc.
The setup makes a difference yes, but it's only the last few seconds.
