Everybody who have imported large amount of data from any cad system know that it normally kills the instancing. The intention of this script is to find geometrically identical nodes and instance them. This script will of course work if someone have used copy instead of instance in a scene and wants them instanced instead.
I'm happy to see that so many have tried out my Sunday hack that I made 5 years ago...but as it was only something to do for a Sunday its not really something I support. I would love to, but my daytime job takes all my time ;-)