I usually try to get most of it done with autosmooth, picking smoothing groups by hand feels like a waste of time... You could also check out this script: http://www.scriptspot.com/3ds-max/scripts/hard-soft-edge It adds soft/hard edge functionality like Maya has, it's a lot easier to work with I find.
All smoothing groups do is decide how the normals along edges will smooth, hard or soft. If these polys are in this group and its neighbors are in another then the edge between them is hard/broken. If they share groups then its soft/unbroken. You can have a bunch of broken edges with only two groups just by assigning every…