Helped minimize impact on treadmill; works as advertised
So when I bought these, I was worried because of the lack of reviews and that it was all based off what I saw on Shark Tank. I took a leap of faith, and figured out an easy way to test this out to see if they did what they claim to do: I put one in on one of my running shoes and left the other shoe alone.
I conducted my "test" by running on a treadmill at the gym. I can honestly say that while running, I wished I had both in because I did notice a difference. I felt less shin and knee pressure, and also less hot spot area friction on the Noene shoe. On the other, it was normal. I am a 6'4'' 240 lb nonrunner (mostly stick to weights) so it is important for me to minimize the impact of treadmill running on days that I use the treadmill for HIIT.
In conclusion, I am happy enough with the results from my one trial that I am keeping the product, and I have it in both shoes now. If you have chronically bad knees or issues, this isn't going to solve the issues. It does seem to minimize impact and lessen stress though, and for that I feel its worth the somewhat high $30 price tag.
UPDATE 7/21/15: I am still loving these inserts! They have made treadmill running so much easier for me and I don't have any aches or pains in my feet, shins, or knees afterward. The price tag is too high for me to get them for all my shoes, but for the high impact of running, they are a must have in my opinion.
UPDATE 12/4/15: Still enjoying the inserts. They've helped up with no issues, haven't bunched up on me, and I continue to be able to tolerate running on a treadmill (as much as any normal human can tolerate that evil machine). Still no regrets.