I have the calcite leather and have been concerned about deterioration since my C70 is never out of the weather. So far there are no cracks, discoloration, brittleness, or fading. I hope to keep it that way. I clean it occasionally with mild soap and water and soft cloth for drying. Anyone who has found a product that is kind to the leather while providing lasting suppleness, finish, and easy to clean protection, it would be helpful to hear about your experience.