The chair itself seems OK so far but this is the THIRD Dexley chair I've had! The first 2 were delivered damaged-in-the-box (same piece each time: the plastic shroud that covers the bar that connects the back to the seat). The only reason I have it now is that I had the store personnel assemble it for me to be sure that the same part didn't arrive broken a third time.
Headrest does not adjust up or down sitting in the chair the headrest pushed in on my shoulders I'm 6'3". I ended up leaving it off. Noted on the instructions it's listed as an 'optional' piece. Not a big deal overall. There seat cushion just the stretched flexible mesh. After a few hours of comfortable sitting I find it begins to feel a bit tight in the hamstring I'm 185 lbs. I'm a little concerned that the material will stretch overtime. The lumbar support raises but during use (leaning back at times) it clicks down the notches until its a the bottom again. In short seems like it'd be a good chair for an average sized fellow. If you're taller I wouldn't recommend it.