@Robusto well true, but what is the part of power used when pulling feet upwards? must be something <5% (
The Best Cyclists Don’t Produce Power When They Pull Up on the Backstroke ), also there are traffic lights and other reasons to stop 2 or 3 times, and getting another pair of shoes with you is annoying, if I were not going for work I would prefer pedal with fixations too, but in my case they are superfluous