Do they claim to make you 4% faster - and can you quantify/verify this?
How come you don't record which run you do in which shoes anymore? It would be interesting to have some stats on the Vaporfly....
Most of my runs are uploaded automatically from my Garmin, but my watch is not smart enough to know what shoes I wear.
I ran this 2km relay with my Nike 4%'ers in 6:23, compared with 6:30 last year. That's 2% faster and I'm also 2% older, so that makes 4% :-)