Basement_Lurker
One who lurks
I found this report on a number of low flow toilets and it seemed to be fairly extensively done and it encompasses a number of different makes/models:
http://www.crd.bc.ca/water/conservation/household/toilets/documents/MaP_10th_Edition.pdf
http://www.crd.bc.ca/water/conservation/household/toilets/documents/MaP_10th_Edition.pdf