I only know of one person that has used the shredded rubber mulch and they have pretty much hated it. It was expensive, and apparently it smells and makes a mess of clothes. They may have bought the wrong stuff though, I think theirs was literally shredded tires. I finally went with about 8 inches of wood chips in the bottom of the hole and finished with about 4 inches of "playground mulch" on top. I just bought this house a few months ago and I don't know if the land is always so wet or if it because of the biblical amounts of rain we have had lately. Whatever the case, this experience has caused me to decide the improve the drainage of my property. I have no idea how but I'm hoping somebody here will.
Rick
Rick