The Quad Chamfer modifier produces all quad chamfers, unlike the normal 3ds Max chamfer which produces a lot of triangles and ngons.
It is the successor of the Quad Chamfer maxscript, improving on by:
Speed. Being a native c++ plugin now it allows you to modify chamfers in real time.
Control. You can determine the look of your chamfers by controlling their sharpness/roundness.
Robustness. A robust new algorithm allows you to chamfer any edge combinations without unpredictable results.
Flexibility. You don’t have to commit to any chamfer, you can always change them later.
Workflow. Besides using edge selection you can chamfer by smoothing group boundaries or edge weights. This way you can edit the underlying topology without losing or destroying your chamfers. Also chamfering by edge weights allows to have variable widths on your chamfers.