Has anyone tried AntiGravity Yoga available at Crunch in NY, LA and Miami? According to the Crunch website, an "AntiGravity Hammock acts as a soft trapeze, supporting you as you master simple suspension techniques leading to advanced inverted poses. Perform advanced yoga inversions without neck or back compression." The photos are wild: www.anti-gravity.com/yoga/index.html. What do you make of it?