I have had this chair for less than a year and it now drops in height on its own. It says it should hold 287 lbs and i definitely weigh less than that, and it still drops down on its own. It’s very frustrating. 
However I chatted with an agent and she was willing to send me out a replacement to fix my chair. That says a lot about how much they value us. 

Other than that, I love the chair, it’s comfortable, nice, elegant, and goes well with my living room space and my desk.