I was looking into the MyoChair recently and some reviews said that the seat cushion was super uncomfortable. But I don't know if that is just a "larger person" issue.
I wish my boss would spring for some better chairs in our office. I am sitting in a 10-year old Staples chair and it isn't doing my any favours. He is literally the cheapest person when it comes to office supplies - good luck to getting a better chair unless I buy it myself