I have a hard time believing the 2-3 seconds per 1500/mile.
You really telling me Gudaf Tseguy, who wasn't wearing new spikes, would have done a 3:50 indoor 1500 if she were in DFs? That's equalling the outdoor record by 2016 super sketchy Dibaba. Outdoors that would be like Tseguy running a 3:47. That if only she'd had Nike spikes she might have beaten Kipyegon and Hassan in Doha 2019??
Also worth pointing out that despite both Muir and Dibaba having DFs since beginning of 2019, neither of them have PB'd outdoors at 1500-5000 distances.
Also worth pointing out Timothy Cheruiyot hasn't PB'd in the 1500 despite having DF's since 2019.
The spikes are awesome - I've got a pair - but I don't think they're in the same ballpark as the road shoes (my road PBs have dropped, track ones haven't, though haven't got injured since I got them).