Kipchoge actually ran 2:04:00 (in Berlin) with that insole issue. With super shoes, 2:01:39, improving the world record by 3 s / mile. Including Kipchoge, only 4 people so far have bettered Kimetto's 2:02:57 from 2014.
So based on that, the super shoes give you 3 s / mile at the very top. If we think that Kipchoge and Bekele are THE super stars, then rather only 2 s / mile. Note that the third best now is over a minute slower than those two, while back in 2014 Kimetto was one of five sub-2:04 runners.