Decent Product--Time will tell.
I used this for 12-in ceramic tile.  I only had 3 spare tiles from the tile installation, and had already used those.  I noticed grout breaking up at a corner and found a total of 10 tiles, roughly in a square, that sounded hollow.  I drilled one hole on each side initially.  My one little tube did not do the job.  It is only 10 oz. and there is significant waste with adhesive exiting the holes.  I had trouble getting the product to easily flow under the tile as shown in the video.  I wound up drilling more holes until I got what seemed adequate coverage underneath.  After 24 hrs, about half of the tiles still had spots that sounded hollow.  I drilled 32 holes total.  I used a 1/4-in. masonry bit which jammed frequently when trying to drill.  (The tiles are set with those little spacers which are not exactly 1/4 inch. )  A 3/16-in. bit MIGHT work better, but I did not have this size. The tiles are down much better than before.  Hope they last.  Expect one tube to treat 3-4 tiles.  My job took 3 tubes.  The adhesive seems a lot like Elmer's glue in flow characteristics and tackiness.  Cutting the applicator tip is important.  It needs to fit snug inside the drilled hole without bottoming out.  Start with a narrow tip and shave off slices until you get it right.
Rating: 4 stars