Just an update: now I have seen Ka, and my opinion of Zumanity remains the same.
I think I know why Zumanity doesn't stand out. It's not so difficult to find super-hawt performers. It's probably not so difficult to find amazing Cirque Du Soleil-type performers. But it's probably *VERY* difficult to find super-hawt performers of Cirque Du Soleil caliber, judging by the Zumanity performers.