I tried one of these in August and did a review on it:
http://katilea.wordpress.com/2010/08/22/dragon-demo/It's a great chair if you are small adult or for child (snapdragon). The owners are really nice and willing to customise their chairs for you in any way they can.
I was just on the weight limit though and I found the Torque controller difficult to control, it also didn't have recline and after seeing it I relaised I would not be able to manage changing over the seat/standing frame myself, so it's not suitable for me personally.
Great for kids though particuarly cos of the function to lower it right down to the floor so kids can play on floor like other kids.