Installer Certification is a must
Although it technically is concrete, pervious concrete has unique properties that cause it to behave very differently. As such it requires a completely different set skills and knowledge that can only be acquired through completion of the certification program and hands on experience with the product. The NRMCA is the certifying body for pervious concrete, be sure your installer is certified AND has several successful installations you can go see.
David Liguori - Bay area pervious concrete