It's not just consistency. It's grind size distribution. The cost of a high end burr grinder is crazy and I don't understand what's going on but you can do simple comparative tests.

I have a 2 different burr sets for my grinder with different cutter geometries and the mechanical properties of the grinds and the puck are different. Never mind the taste. The way the water pours through the puck and what's happening inside the basket as you pull the shot is different. You can easily tell by the amount of channeling I get and the integrity of the puck after the shot.

The espresso also tastes different BTW.

I've also done blind taste testing with my grinder pitted against 3 other grinders. Having only tasted the coffee from 1 of these, I matched the coffee to the grinders only based on the theoretical properties of the burr sets.