The thing I miss most when I ride with platform pedals is ability to pull up on the crank while climbing a curb: you ride up along-side the curb (curb-side pedal up!), clip out on the curb-side foot, step onto the curb and lift/swing the front wheel up and over the curb, while pulling up on the street-side pedal. By the time the front wheel is pointed away from the street, the clipped-in foot is in position to push. The rear wheel climbs the curb and the bike shoots away. It's pretty smooth and quick.
This is handy when you need to exit the roadway efficiently, and is much less dramatic than trying to bunny-hop up onto the curb.