I second Rick's question regarding play in the cleat/pedal interface. That is something I have always wondered about with Coombs...is there a little for/aft slop when pulling through the bottom of the pedal stroke or extending over the top? And how does this the minimal float transition to pedal release? Is there a gradual build up of any resistance, a sudden stop before release (like on an SPD), or nothing at all to differentiate clipped in/out other than foot angle (like Speedplay Frog)?
Can you shed any light on this dwaharvey?
@Matey, regarding your question on spindle length, I am not sure of the exact dimensions on the SPD-SL series but, generally speaking, shorter spindles will provide you with a narrower spacing between your feet (often called "Q factor"). Many people believe this to be more ergonomic, however there are many exceptions to the rule, for example Mark Cavendish has custom extra long spindles in the Dura-Ace pedals, and Armstrong used to put spacers between his pedals and cranks to widen them, apparently to relieve some back pain he was experiencing.