You can remove the insoles from Allbirds - I removed mine and put Powerstep insoles inside. If you have a high instep, you will want to pay attention to the tongue - some have a true tongue, and others are essentially slipons. Both my husband and I wear our Allbirds for travel, but the one big issue we have is that most of the shoes have zero grip. In wet conditions, they are like walking on ice. The Tree Dashers have decent grip, but the runners are slick.