True offset option to postion, rotation, transform and child of constraints

It would be nice to have true offset options for these constraints, similar to maya. Currently setting up a true offset constraint is dealt with by copying a bone with the exact orientation to another bone, making it a child and then hooking the constraint to the parent. In cases where you would like to retarget one armature to another, this is needlessly complex and time consuming. By adding an offset option that becomes the master orientation an positional control, you'd alleviate a lot of headaches. Even with Child Of constraints, you'll get a double transformation if you aren't careful on building the target rig perfectly.

Doing most of my work in Blender, I've come to miss the ease of use in Maya's constraint system and feel this would benefit first time users comfortable with other constraint solutions.