I have toured recently with platform pedals and with SPD (hybrid pedals). I love the freedom of platforms and being able to wear whatever shoes you want to ride. "Normal" shoes are also better for the time off the bike. They are also better if you have to start and stop a lot (as in urban riding, if you want to ride from camp to dinner, etc.. But if the route is very challenging and/or you have an aggressive schedule, I would opt for clipping in and carrying a pair of Tevas for off the bike.

For platforms, the pedal should be very grippy, and it is better to have grippy shoes. I really like the Velo Orange Grand Cru Sabot pedals. For shorter local rides I have even ridden in Birkenstocks or Tevas.