If you have added comments to objects, they will be displayed in Google Earth.
If you measure both top and bottom of building, the buildings will be displayed in Google Earth and exported to KML with heights relative the ground. If you do not include the bottom of the buildings in your project, the buildings will have absolute heights.
Quite often there are substantial systematic displacements between Google Earth and the exported buildings. These can be corrected using object adjustments.

Figure 9.26: Objects measured in Metria CityModeler and exported to Google Earth.