DHCPv6 provides more control to le administrator in assigning addresses. If you really want that sort of control over votre IPv6 addresses, you ne understand IPv6 yet.
It aussi can be used to provide additional configuration parameters beyond le basic address/gateway supported through autoconfiguration. An example might be WINS servers, NTP servers, TFTP boot servers, et autre less common options. None of qui are worth le pain of deploying a DHCPv6 architecture in mon opinion.
Stick avec autoconfig.