These are very similar to Hawley retainers in that they are both acrylic and metal. These are made in the lab to create larger tooth movements.
Spring retainers are good for limited tooth movements. They handle rotations better than the Hawley retainer.
Basically, this type of retainer addresses movement in the incisor area only. This is their biggest limitation. If rotations are present from the cuspid (canine) back to the posterior teeth, the spring retainer will not be able to make corrections in that area.