We ordered 8 of these chairs for our office and have had them for over three years with no issues with any of them. The chairs are very comfortable and quite durable. The only issue I have with them is the headrest is a little awkward. It's too short for tall people (>6') and sticks over the back of the chair for short people. Some people just took them off (which is really easy) but not the end of the world - still a great chair.
This modern looking chair came with very good instructions. The screws were all individually packaged and labelled with letters. So it would be hard to mix them up. That said I was only disappointed that the allen wrench screws seemed of an odd size that my power drill couldn't accommodate (and I have a bunch of screw heads). You need to put it together upside down and it's somewhat heavy - but I managed to do it with no help. The chair is very adjustable and high end feeling. The casters roll nicely. It was perfect for my ailing back and neck.