I bought this chair in October sit an average of 11 hours A-day. Paper and computer work all day. Outside of actually just sitting too long I do find it pretty much comfortable and a good desk chair.
The only real problem I had putting it together was getting the wheels to go in. Otherwise now that it's all together I love it! It's very similar to my office chair at work which doesn't exhaust me that's why I bought it.
I chose to assemble the chair opting out of the rather high charge for the store to assemble. Some drawings in the instruction booklet were not clear and some screws were bent and some of the threaded holes were off center so the screws were difficult to tighten with the included hex wrench. One couldn’t be completely tightened with a socket wrench.