Either way requires some additional effort.
The default group I think was suggested previously and will enable others to more easily make changes. However, groups are not mutually exclusive so someone could place a computer into mopre than one default printer group. This would cause potentially some confusion and may be difficult to track down. This approach needs to have a group management methodology in place to find duplicate entires in your default printer groups.
Using the PrimaryGroupID would eliminate this issue since it can only hold one value. You will have to add code to convert the RID of the group to the name. As mentioned in the other thread you could use some of the approaches listed there.
