Add 2 minutes to every marathon in the super shoe era to compare to times run in the previous 25 years.
Emma ran 2:18:29 today. Add 2 minutes to that and you get 2:20:29. Deena ran 2:19:36, so Deena is still the fastest American female in the marathon.
The shoe used actually matters. Shoe/athlete interaction also matters. Everyone has a different benefit. 2 minutes has been the benefit for ~2:20 runners/1000th fastest man in a calendar year on average pre/post super shoe, but we know that that represents the most popular supershoe - the Vaporfly.
After some back and forth in the other thread, it looks like she was wearing the NB FuelCell SuperComp Pacer (in a unique, white colorway). It has a lower stack compared to most super shoes, and only costs $150 retail. I haven't seen any lab test results that would determine if it is a super shoe or not.
I would think they have to be better than whatever Deena was wearing but I seriously doubt they are anywhere approaching marathon supershoes like the Alphafly/Vaporfly. They are probably closest to the Adidas Takumi Sen which I don't know that I've seen worn by elites in a marathon.