First iteration - no spikes
Second iteration - w/ spikes for grip
Have since been testing mainly. They’ve been working really nicely. Actually borderline too good. I had to loosen my bindings way up to be able to slide out of them; otherwise my shoes would stick. @skate420 took them for a spin when we road some sweet sweet single track trails in her hood. She seemed to like them.
Edit:
Washers give a more stable (i.e. steel vs tpu) mounting hole for the spikes