I am on the shorter side (5'2") so that chair fit isn't perfect. The lumbar support can't be adjusted. The support sat just above where I needed it so I ended up ordering a seat cushion (which put the lumbar support at the proper height). I ended up putting the arms on backwards so that I could move in close to my desk. The seat cushion is comfy and if you are taller the addition of a cushion might not be necessary. The seat pan sits right behind my knees again not shorter person friendly. Since I have to use a footrest the seat doesn't hit the back of my legs so I don't mind. Although the seat pan doesn't slide back and forth I could move the seatback forward to shorten the distance between my back and the end of the seat. However it's a little uncomfortable to sit straight up. If you have longer legs it should support you fully. I like that it can lean back or lock in place. You can also lock the seat in a reclined position. I've only had the chair for a month so time will tell. So far the seat is a good buy and provides decent ergonomic support and adjustments.
I bought one of these chairs as a staples special over 7 years ago. The mesh in the back is separating from the plastic but I still use it every school day as I grade papers and lesson plans. I decided to buy another (this time much more expensive) and it’s exactly as the other. Comfy and solid.