I've eaten plenty of breakfast cereals in my time and I can say without reservation that there is no worse breakfast cereal than Grape Nut Flakes.
Sure, Cheerios smell awful and Uncle Sam cereals taste like they've gone rotten in the box, but for sheer tactile disfunction, nothing beats Grape Nut Flakes.
To whom did Post test market that product? Those without teeth? Did the testers say, "Could you make the cereal turn to mush when I just wave the milk near the bowl?"Grape Nut Flakes turn to mush as soon as they even sense a liquid nearby. And, once they turn to mush, they also lose any flavor they once had (not much to begin with). So, once you pour a bowl of the cereal and add milk, you end up with a gelatinous mess of milk and sludge with no flavor beyond that of the milk. Mmm.....
I eat great mountains of cereal for breakfast. It takes me, on average, two and one half-days to empty a box of cereal. It took me six days (!) to get rid of a box of Grape Nut Flakes, though. It was like my own personal version of Breakfast Hell. Every day for nearly a week I got the chance to relive my horrible decision to try a new (to me) cereal.
From now on, I'm sticking to old, reliable, Frosted Mini Spooners. They're sweet, high-fiber, cheap, packaged in a bag (no enclosing box; less waste), and tasty.