Usability of measurement in Creo 2 decreased in some points compared to Wildfire 4.
Measuring distance with projection: the projection distances are no longer displayed as lines in 3D. In case of coordinate system as projection reference they were colored with rgb colors, which gave a very quick orientation. In large assemblies this feature would be helpful, especially if the projection reference was selected outside of the current view port (e.g. coordinate system in the model tree).
Explicit close of measure tool is inevitable which yields to additional mouse travel.
A replacement of measure references needs extra menu operations. In Wildfire 4 it was very easy: the first click on the base of measurement and the following clicks tho inspect several distances. Perhaps the shift key can be used to replace the measure reference, which was selected last.
Sometimes the result window is displayed behind the measure window. This should be avoided.