I have used New Balance 763, 768 and 760 model shoes without any problems. I switched last year to the 890 and after experiencing discomfort in my knees, I then tried the new 860 model, the successor to the 760. Better than the 890, but I experienced the same problem after some time. I noticed that the heel construction and strike when running doesn't feel as even. I'm back to using my 760's and things are normal again. Has anyone else experienced a similar scenario with the 860 (or 890)?