Product review (5 stars): Works great, a little work to set up.
They work well and grab the granite as stated by the name!  (See below for more detailed installation notes.)  My original brackets came off after less than a year and they were installed by the granite installers!!  It looks like these will last a lot longer than that!  I had to scrape off the old silicone glue that they used before so keep in mind that I installed it over that glue residue as well and it still held firm.

After reading several online reviews I decided to clamp the grabbers on for minimum 10 minutes and no more than 1 hour.  I ended up about 10 minutes and they seem to be situated just fine.  I would have liked to use them the way they suggest because as it is I ended up being a little crooked when I got the dishwasher back in.  I think if I were to do it again I would place them as suggested and THEN move out the dishwasher and clamp them on for about 10 minutes each (on each side of each clamp also) before replacing the dishwasher.  I also read that you should not use the dishwasher for 24 hours.  I used it right away and it was fine, but I think I would wait at least 12 hours if I had placed them evenly.  (I am kind of hoping they will come off so I can get new ones and adjust them).