A chair should be comfortable enough to keep its users spend maximum hours sitting on it. Looking at office scenario's, opt for a chair with wide dense seat pan and a high back.
A mesh back will help you in eliminating sweat patches. Make sure that the dual caster wheels are made of nylon, capable of traversing over all floors.
The pneumatic adjustment must help you in adjusting your chair as per your comfort. Arm rest with a padding will help you maintain your balance while sitting and reclining.