Clone and Place : 3ds Max utility script
This utility script replaces selected objects with instances of a specified object or hierarchy. Because I'm lazy, there is no undo for the "delete selected objects" function. BUT: You can choose not to delete the objects being replaced, just to be safe (the default behavior).
I find it useful to leave the original objects to check rotational orientation. I developed this to replace low-res Revit geometry with nicer high-res geometry, and when replacing objects with different rotational orientations, my source models don't always end up the way I expect. The replaced models are all instances, so it's trivial to edit them at the element level to correct X/Y/Z alignments. One known weirdness: the instances end up not numbered sequentially. The names are unique, but your source object gets renamed too. Maybe I'll fix that some day...