The last two weeks we had time trials in 3k and 5k. I wore Vaporflys for the first time on a track in the 3k, and it just...wasn't what it was made out to be. I basically chalked that up to the fact that it was a 3k, which is obviously very short for VF's, and they just felt clunky running 4:30 pace. I really only wore them so that my legs would feel fresh for the following week, since I heard they help recover (which actually was 100% true, my legs felt super fresh).
So I put them back on a week later excited to wear them in a 5k, and...same feeling I guess. It underwhelmed spectacularly and I felt I could have probably ran faster in spikes. Honestly I'm glad I wore them in time trials rather than real races because I would have regretted it more if I had wasted a real opportunity testing them out.
And for anyone who's wondering, my times were 8:36 and 15:07, when my PR's in the events were 8:35 and 14:55. Both ran in spikes.
Maybe it's just me, but I don't get the hype over them on the track. I've never ran a 10k on the track so I can't say anything about that, but I don't understand why they became so popular amongst college athletes in 3k and 5k, the only benefit I saw was reduced soreness, at the expense of adding a few seconds to my time.