Folding pedals are great for compact storage, however they are the weakest link on a folding bike. They use smaller bearings due to the fold. The small bearings are more susceptible to failure than standard larger bearings. Hence pedals have the highest failure rate of all parts on folding bikes.

Folding pedals fail with higher frequency, but they can shave a few inches off of the folded size of the bike. Minimizing the width is essential for compact storage. Overall, I try to never fold my pedals unless absolutely necessary, to minimize stress the part. Once I feel a wobble I swap them out, since riding with warped pedals can lead to injury. Overall, I would recommend keeping folding pedals unless you live near a beach with sand. The sand enters the bearing cavity and does damage fast. Sealed bearings on standard pedals are best in sandy environments.