A rotary drill bit or other drilling tool for drilling or reaming through subterranean formation and comprising a body comprising a distal end and gage areas near a proximal end thereof and comprising longitudinally upward extensions of a plurality of blades or legs. A longitudinally trailing, radially inwardly extending surface is associated with at least some gage pads or legs at the longitudinally trailing ends thereof. Protective structures in the form of superabrasive elements comprising a plurality of thermally stable polycrystalline diamonds, or so-called “TSPs” (thermally stable products) are secured to a trailing surface of at least one gage pad. PDC elements may be employed in combination with the TSPs. Non-diamond structures may also be employed, in lieu of or in conjunction with diamond structures, particularly if drilling of ferrous metal casing components is contemplated.