My first and only clipless pedals are SPDs. I have the perhaps misguided idea that this system is slightly easier on my knees than the standard road pedals because of the additional float they allow. I am pretty satisfied with the pedals, but I would like to upgrade my shoes. I bought the Specialized Tahos, because I thought I might walk in them, but I don't, and they are heavy and flexible. I was wondering if anyone used SPD's and was happy with their shoes for LD.