I ordered a Steelcase Criterion char from Madison Seating and learned some hard lessons when attempting to get replacement parts (wheels).
Per the policy page, http://www.madisonseating.com/terms-of-use.html, "Open Box" simply means that the item has been removed from its original packaging. The chair was returned, refurbished, reconditioned, or the price has been reduced due to an overstock of open box inventory.
But, what they do not tell you is that the serial/model number tag will also be removed from the char. Per email interchange "again, the serial number must be removed as the chairs are not covered by the Steelcase warranty". Without this information it is very difficult to get replacement parts. It is also very difficult to determine what chair was actually purchased. Although a current Criterion chair sells for ~800 and Madison Seating sells their open box version for ~150, Steelcase (based on photo) estimate that my chair was made in the 2000s based on pin configuration in the base.
Bottom line, I would not use Madison Seating again for any 'open box' item or any other chair that is not covered by the manufacturer's warranty.
Madisonseating.com offers a 10 year warranty with any open box purchase. The warranty will cover all parts of the chair, (same as the manufacturer). As C. G. points out, the Criterion chair retails for close to $800 and is being sold on our website for $150. We guarantee the chair will be in brand new condition with our 30 day money back guarantee!