You can ignore these comments if you're already aware of this but there are three types of running shoes, stability, neutral and motion control. I ignored this for a long while until I had my running form analyzed for free at Running Room. I was told I needed stability shoes and no longer have pain under my feet.

I saw a documentary that showed that the bio-mechanics of running and walking are different so running and walking shoes are also made differently.

I usually use hiking shoes to have a hard outer sole and some support for my ankles when I'm biking. But I haven't tried my Shimano PD-T400 pedals and SH-CT40 shoes yet. I know the T420 shoes are flat on one side but read a few complaints on clicking although I don't know if that was just a temporary manufacturing defect.