When not barefoot, I was wearing Xero DIY kit sandals for years.
I wanted some more sturdy sandals, to hike in more technical trails. Those are perfect, good grip, excellent fitting. Once set up nothing moves and the sandals are extra comfortable.
There were some strings that went loose, or were chafing, I either repositioned the straps or used a lighter to melt them and pinch them flat, problem solved.
For mountain biking I reused my Xero DIY and was aware of how much more light and comfortable those Pies Sucios feel, because the toe strap is flat and everything sticks to your sole and feels like a second skin. The sole material makes them much much less slippery underfoot than the Xeros, and walking on sloped terrain is less taxing on the straps.
Some small ameliorations though ; they can get smelly (but wash easy), getting them on is slower than with the Xero, the sole could pick up less stones.
Looking forward to replacing my Vivo with their office shoes!!