I don't do mush made made tile work, but I was called in by a hotel with 2' square porcelain  shiny tiles to remedy some heavily traveled areas.  The tiles are about 5-6 years old.  The tiles are indoors, but it is on the beach so sand has dulled out the tiles in some heavily traveled area; like, in front of the elevators and the entryway.  After a thorough cleaning I would like some of your ideas on what options I have to brighten up (make shiny) the worn areas. 
Some photos are attached.  The first photo is of an area that does not show much wear and the reflections are very good.  The other photos have bad reflections and even show picture framing.  The Dir of Operations would like to stay away from a topical that would wear off fast and require too much upkeep.  Is there a topical that will last a long time and look good too?  If I spot treated these large areas, would they closely match the adjoining non-treated (with a topical) areas?