The construction of the better chairs has an all wood frame with wood blocking for stability.  This helps to keep the mechanism firmly in place.  The better chairs have a seven-point mechanism whereas the lesser quality chairs have only a three-point mechanism.  While there is much that can be said about chair construction, the basic difference is between wood frame vs. particle board or cardboard that are stapled together!  I highly recommend that you invest in the best quality chairs you can afford. It will be a much better investment and they will last far longer and be far more comfortable.  Leather or faux suede upholstery are the most practical for durability and easy clean up. - Alexander Interiors, Northern Virginia