The KMZ is a 3D KMZ file that has the texture built in. You might want to look into using the OBJ file with the JPG texture and MTL for alignment. People have had success importing them into SketchFab for example.
The KMZ has been limited to 250000 faces since there is a limit to what Google Earth can display nicely. It can still take a while for it to load and it can sometimes come up under the existing surface when the elevation is slightly off.
Remember that the X and Y axis of the OBJ file is in degrees and the Z is in meters.