2013 Bikes

The science behind that seems a bit sketchy.

Reducing rotational weight.

It's an axle... and regardless of whether the bulk of the pedal is on the pedal or in the cleat it's still going to go around whenever you pedal.

Hurts my head trying to work out the advantage.

Sure, reducing total weight might be arguable... but seriously, moving weight from pedal to cleat isn't going to do a great deal when the in-operation setup will still see the same weight moving.

As folk seldom hang there shoes on the scale when taking WW pics of their bike. It makes a massive difference.

....now if the could make crank arms a plausable part of the cleat......