That's where we get the MaP ratings from.
They test for how much "media" can be flushed consistently without plugging.
What they don't look at is:
Availability of parts
How easy it is to make repairs at a later date
Whether there is a class action suit against a model of toilet
Perception of quality and appearance.
And really, if a car has a 350 cubic engine, is it always better than one that has a smaller engine?
If that were the case, the the car I took up sking with have the large engine, even though the rear tires would spin on snow.