all configuration items under Policy will be synched. You are right that the settings under Configuration are not synched. This is due to the fact that you may have different appliances in different netgroups in different location etc. Therefore every appliance have to be configured with this information according to the needed.
MWG v7 is more modular and specific to be customized therefore i would suggest this was changed.
There are certain items you may not want to be shared, like the IP address (obviously).
MWG6 had items which were not shared as well, but it was less obvious what items those were. MWG6 also had issues exempting items which you did NOT want shared.
At least in MWG7 there is a clear distiction of what items are shared (policy) and not-shared (configuration). As Stefan said, MWG7 is more modular, giving you the ability to make each appliance their own if needed.
Perhaps down the road there will be an option to share certain settings between certain nodes/groups.