Please disregard the sliders on the left hand side, as they are broken.   Prefatory Notes: I purchased this product and am therefore not so easily oblivious to the effects of buyer’s remorse potentially inflicted upon me, unlike those who received free review units and are more liable to completely fall prey to the novelty of new gear.    I say this so that prospective readers looking to find out if the QC20/QC20i is a worthy purchase can read about it from someone in a more relatable position, which is invariably less in those who received...