Originally Posted by
alcjphil
The biggest problem with any clipless pedal system is shoe comfort. Good shoes have very stiff soles, so stiff that you cannot tell what pedals you have. It is the shoe that supports your foot. All that the cleat and pedal do is to attach things together
This is by far the main thing. After this, there may be subtleties that are more important/noticeable so some, like how much movement the shoe has with respect to the pedal in various directions.