I agree that clipless pedals don't have much of a speed advantage for a commute but they do help me accelerate across an intersection and I just feel more secure in them. I have double-sided pedals and use warm regular boots in the cold and wet. Warm clipless shoes are outrageously high priced and the overboots are a big pain to use.

When I first went clipless I stopped at a crosswalk leaving Denver's busiest park and leaned over to punch the pedestrian crossing button and fell over. I ended up on my back with the wheels pointing straight up. A woman runner stopped and asked me if I was OK. I said, "Yeah, I'm just a ****."