I ride a ‘Bent Trike, which came with pedals that had straps. Pedaling a ‘Bent uses a very different motion compared to an upright, and my feet slipped out and off the pedals a few times. I switched to Bontrager shoes with SPD recessed cleats. Generally very happy (I had to walk a couple of miles once and it was fine).
For my first RAGBRAI I have ordered a pair of Shimano sandals, also with the recessed cleats. Should get them soon. My cousin (40 or more RAGBRAIs) swears by them.