It would be helpful to have property sets integrated in all places they could be used. Let's do some research to discover where they can be used and let's make it happen please. 3 examples would be Point Groups, Description Key Sets, and Point File Formats.
Point Groups
With the introduction of the ArcGIS Connector, we are importing data wit multiple attributes. We should be able to use those attributes to define Point Groups. Sure the ArcGIS Connector can map to User-Defined properties, but this feels like a workaround to me. It should really be easier. Something like this. Include options in the Include and Exclude tabs, and allow for queries.

Description Keys
We should be able to apply description keys based on property set values.

Point File Formats
Point file formats map information in an ASCII file to Civil 3D properties like northing, raw description, etc. ASCII files sometimes contain point attributes; let's have the ability to map these attributes to property sets.

Can you think of more places?