a few more thoughts on platforms, more properly called flats. Some people just prefer them over any kind of clip in, for comfort and security ( is, NOT being clipped in) Many mountain bikers that go this route often wear a shin guard as a flat will pretty typically take chunks out of your shins. What I see as the main difference is that you don't have the pedaling efficiency of being clipped in, but at the same time that gives you freedom of the feet.

As for shoes, find the style you like and then go for fit, that's important. SIDIS have tread shaped configurations on the bottom but it's not a terribly sticky plastic.