I've been using this particular setup for a while now, I've had the GeekDesk for over a year, and the Aeron chair for 5 months. My favorite part is, as you can imagine, using them together. I've got a bulging disc in my lower back, so I figured there'd probably be a lot of people who are looking for relief for similar types of issues.
Update 9/19/16: I recently helped a client get their Geek Desk set up and rearrange their office, and I have another testimonial to share:
"I just wanted to send you a note to thank you for telling Michael about your desk, and for helping him to get his new desk, and all the computer stuff hooked up! Without you, he would not have this new chance at less back pain."
- President Dwight Eisenhower