As advertised by Brooks these shoes have helped with my knee pain while running. I don't know if it is the GuideRails system or that I am focusing more on where my foot is striking while running. But since I have had these shoes my knee pain while running has been gone. I have done 5 runs in them so far and each run has finished without my typical knee pain. The fit is good for me I normally get between a 11.5 and 12 mens, for these I got the 12 and it is a good fit.
If you are a casual runner with knee pain give these a try and see if it helps you as it did for me. I will be getting another pair when these wear out.