Difference between BRepGProp::VolumeProperties() and BRepGProp::VolumePropertiesGK()

Hi all,
I currently use BRepGProp::VolumeProperties() to calculate the mass of a solid body. Code snippet is below

GProp_GProps props1;
BRepGProp::VolumeProperties(solidBody, props1, 1e-3, Standard_True);
double mass = props1.Mass();

While this worked correctly for most of the cases, several cases didn't return the desired mass value from this. I then exported the solid body and inspected the mass using other software (SolidWorks, Salome). And they returned values which are around 2-3% different from OCC.

Then I switched to BRepGProp::VolumePropertiesGK() to calculate the mass. The method is the same as above except the following

BRepGProp::VolumePropertiesGK(solidBody, props1, 1e-3, Standard_True);

This turned out to be returning the desired mass properties for all the cases. I then checked OCC Document to find the difference between these two approaches. However, most of the desctiption in VolumePropertiesGK() is redacted. You can find it by here:

https://dev.opencascade.org/doc/refman/html/class_b_rep_g_prop.html

My question is a 2 parter,

1. Is there a significance difference between these two approaches?
2. What does it mean by redacted descriptions in OCC Document?

Thank you very much