That feature has been there for a long time.
Select all your fixtures you would like to know about. Then right click on the little notpad icon. It will bring up infomation on the slected area.
Number of fixtures -
Patched used -
Layers -
Total Weight - (doesnt include the bar)
Total Rating - (this is power in Kwatt.)
It would be nice is this was able to be saved or exported. I think from memory that there is a report that also does it by location if you add that infomation the the fixtures location. Hope this helps.