Question on Differences between Rawdigger and ImageJ

When I compare the image statistics between imageJ and Rawdigger, it appears some sort of offset is being applied to the imageJ analysis. I am characterizing my cameras and need to understand this. Rawdigger has good tools for presentation, etc, but cannot do image math like addition/subtraction.

Why would the differences be there? and which do I trust?

Please post a concrete example of what you are trying to do and what you are expecting to get. You post is not informative enough to even understand what kind of analysis you are referring to.