I don't own 3DS max either, I just figured the tool would be extremely helpful.
However, from a quick search I found out that 3DS Max can use US Standard (Centimeters, inches), Metric (Meters, Millimeters) Or custom inputs (One unit could be 100 meters in customs settings.)
However after a few more searches I found out that these are the recommended settings.
1 unit = 1 centimeter (image below is more precise in values)
Not sure if this helps or not, i'm not a programmer
EDIT: I just found this, the standard when you install 3DS Max is 1 unit = 1 inch.
(...Then I remembered that 3D Studio Max has as unit default 1 unit = 1 inch (in System Units Setup -> System Units) and yes, 1 inch = 2.54 cm, a value very near to the factor my models where scaled up...)
http://forums.xna.com/forums/t/6909.aspxit's your choice of which one you choose, which ever one works better in anim8ors default settings.