Definitely Leather. the 1/4" x 72" Tandy Latigo lace is the bomb. I reshaped the soles I had and was able to salvage them then pop new holes. This time I will be more careful adjusting. I replaces the nylon cord laces with the Leather and wow, big difference on the Achilles. No more rub and these aren't even broken in yet.
I used to wear flip flops everywhere but they always felt like they would fall off and I scrunched my toes to keep them on. Same thing with Birks. and there was no way to just break into a run that was one reason I switched to the VFFs, I could break into a run and not have shoes fall off.
Huaraches are ingenious, They solve all those problems.
I still use my shock cord the most but I laced up my first pair with wide, soft shoe laces the way shown by invisible and it's definitely more comfortable. I'll eventually go the leather route, I'm sure, but I really want to be certain of having high quality leather and I haven't found a source wiht exactly what I'm looking for here yet.
The sole is still the old Margaritaville flip flop sole that is about 3mm
They are floppy and I am still trying to decide whether I want the 4 or 6 mm Vibram. I am about 95% leaning towards 4mm with a leather deck and cut grooves fro the leather on both sides through the leather and rubber. The leather deck should make them really sharp. I look at the old used BF Ted huaraches and want them. They look great!