The simplysitting seat just arrived today. I immediately ripped open the box and tried it out.
One word: WOW.
I am a former marathoner and amateur acrobat, with two torn knees and a bulging lower back disk to show for my years of athletic adventures. This seat is allowing me to complete my 45-minute sits with zero discomfort. (Before, I had to do laying-down meditation after 20 minutes, the pain was so intense.)
Plus, this seat is nothing short of gorgeous and elegant.