Simple script, if people find it useful I'll make a gui and add a bit more to it. But the whole premise was to just quickly build a tool I could differentiate big objects from small objects in my scene based on VolSize variable in the script.
What I used it for was to fracture objects for a big landslide for a film, and then I wanted to use this script to tell me which objects were big so I would then work on making them procedurally break more, whereas I didn't want the small pieces to sub-fracture because that would be overkill.