Thanks for the great explanation for clipless pedals and shoes. Over the past few years I moved back to flat pedals and wanted to share the story to those wishing to make an informed decision about their choice of pedals. Some 5 years ago I cycled along the tow-path of the grand union of canals between the great City of Birmingham and the Capital City of London and wrote my story here:
www.harlechjoe.wordpress.com ( archived date May 2017).
Prior to that adventure I always used clip-less pedals with compatible cycling shoes. They worked well, assisted my pedal technique and were very comfortable.
Recognising a risk of falling into the canal and being clipped into pedals would be drowning I fitted double-sided pedals, using the flat side for tow-path cycling and the clip-in side for road work. By the end of the ride I had rediscovered to Joy of cycling on the flat platform and when my clip-in shoes wore out, instead of replacing the shoes I replaced the pedals- photo attached. These grip me just as firmly as clip-less and as all mountain bike users know they are great for powering up steep hills. I also follow adviced given on this forum and upgraded my cycling boots to keep warm and dry in cold wet winter weather.
So in summary, the pedal of choice has to be a personal choice.