I'm familiar with the concept, but I think the flavor itself is kind of hard to describe, and is a lot more subtle than the other basic tastes (sweet, sour, bitter, salty). My understanding is that it tends to amplify other flavors, rather than having much of an identifiable flavor in itself.

But I know it's triggered by glutamates, and it's the main reason why MSG (monosodium glutamate) is added to so many foods as a cheap and easy flavor additive.