So I used the Newtons for a 3.25 mi treadmill run. I didn't have any issues but I wouldn't want to use them for a longer distance until I had a chance to build things up a up.

They felt really good in terms of foot strike on my left but they emphasized the fact that I don't land properly on my forefoot on the right. That's kinda cool because it helped me think about it and adjust a bit, but it was tiring, hence why I wouldn't use them for a longer run. Looking at the soles after the run, I could see where I'm still striking too much towards my heel on the right and how that causes me to put on the brakes a bit.

They are super light and feel like nothing on your feet. I tend to get sore at the ball of my foot at times and you would think that they would make that worse but it actually felt like I had more cushioning there and it was comfortable. My fore foot splays alot in weight bearing but the toe box is quite spacious and I had no problems with that.

As for effort, my heart rate was a little lower than expected given my pace but it's hard to compare because it was a treadmill run after all.

I can't wait to try them out at the track.