The bandwidth statement won't affect your throughput unless you are relying on percentage based QoS or rate-limiting. I would start at each edge of the network and work my way towards the wan. Check to make sure there is proper speed and duplex settings on the servers or pcs. Then check to see if you get fast transfers internally, etc. If you still have speed issues on the wan, what type of latency or packet loss are you seeing?
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...