My boss got one of these back in the pandemic to WFH. He bought several more for the office when we returned and they've been great so I picked one up for myself. Little to no fatigue through out the day and are very comfortable for a long time.
After a week the Seat stretched so much & sags down so far that it's not comfortable to sit in. Leaning back will sometimes cause a loud pop like the plastic is being popped out of place. Avoid it it won't last long.
Chair does support the lumbar well. The back pops when reclining. A sign the screw arrangement is not sufficient. The seat is slightly wobbly on the pneumatic post. A sign the base assembly is insufficiently sturday for the chair assembly. The mesh is not as thick as I hoped. Overall the chair is of mediocre quality.