In most commuting situations, I would imagine that the speed advantages of clipless would be fairly minimal.

I commute with clipless anyway because:

- I love the security/stability of having my feet locked onto the pedals.

- they make trackstanding easier.

- they guard against foot slip when I'm up out of the saddle charging full steam to chase a waning green light.



as for shoes, I simply keep a pair of work shoes at the office, there's no need to lug those back and forth everday.

as for harried, trafficky situations, all of my bikes have combo SPD/flat pedals so that I can ride a regular old flat pedal whenever I want to (best of both worlds as far as I'm concerned, but others strongly disagree). Still, I ride locked in on the clipless side of the pedals more than 95% of the time.