I just bought the new Nike Air Zoom Victory "super spikes" and they feel very different than every other spike I've used. I'm a Masters track athlete, been competing seriously since I was 44, which was 18 years ago. I have been moderately successful (5th in Masters 800 outdoor nationals, 2nd in 400 meter indoor nationals in 2019, hold AZ state age group records in 200 and 400). I've used lots of middle distance spikes, but as soon as I put the new AZV's on I noticed that they have a pronounced "spring" sensation. I ran a time trial this past Saturday, and was faster than I had expected - I believe the spikes made a difference.
I've never posted on Lets Run before, though I read it regularly, but this is a big deal to me, as one of my 2021 goals is to break the AZ state age group record for the 800.