Is this important?
I would imagine so, considering all the parts have datums, but what is the difference from, say, setting a point as Datum A and dimensioning a feature to Datum A, and setting a point and dimensioning a feature to said point?
It depends on what you have your dimension reporting set for... if it's set for legacy it will be the window on the left, if it is set for Xact measure it will look like the window on the right.
It depends on what you have your dimension reporting set for... if it's set for legacy it will be the window on the left, if it is set for Xact measure it will look like the window on the right.