Was gonna swap, but riding city streets, sometimes you simply cannot get clipped in fast enough. With a MTB shoe I can use the tread of the shoe to stabilize my foot on the pedal, get moving, and then clip in. My understanding is that with road shoes, this would be very difficult and possibly dangerous as without the tread, your foot can slip off the pedal if you try this.
Anybody care to chime in with their experiences?