Workout was 12 mile threshold at 5:27 pace. Around the same pace I have run for 10 mile workouts recently so did not see a huge boost in performance. On the first stride of my warmup, I felt how springy the shoes were. Honestly they are unlike any other shoe I have ever worn, and I could tell from the first stride. If I had to guess the shoes probably give a performance boost of a couple seconds per mile. Another noticable difference was that post workout my calves felt much better than normal post workout. Could have been due to the enegery return and not having to push my calves as hard to run fast.
Any questions about the shoes I'll be happy to answer.