It would be nice to have an interactive snapping tolerance tool, where there is a 3D circle around the cursor that one can draw interactively to define the tolerance, but the feedback to us, would be a 3D circle that grows from the center of the user click.
The 2D version is created from a point click and draws outward, but on a flat plane.
The 3D version we could see in 3D, perhaps as part of 10.1.