A very usefull tool in Solidworks is the ability to offset an extrusion (emboss or deboss) from a face, edge, or vertex. This can be important when certain dimensions need to be maintained if other changes are made. It can also make creating certain extrudes much easier and eliminating the need to double check measurements and do extra calculations.
For example, if you had a large assembly that has a flange that was created early on in the design process, but now you have to go back to create a circular cavity for part of a hinge, but you have to be sure the depth of the cut will maintain a minimum wall thickness. Currently, you would have to create a sketch on one face, then use the Inspect tool to double check the thickness of the flange, then subtract the value of the minimum wall thickness from the measured thickness and then use that value to create the cut. If there was an offset extent for an extruded cut, you would only have to create the sketch for the circular cavity and create the cut using the value of the minimum wall thickness for the offset from the opposite face that is parallel to the sketch surface. If the thickness of the flange changes, the depth of the cirular cavity would increase, but the minimum wall thickness would be maintained.
That's probably a poor example, but the point I am trying to make is that an offset extent would significantly cut down on the steps needed to create features.
