If you look at the Physical Properties and Application Guidelines for each, you'll find they are *identical* with the exception of color. And Titebond claims NRND is beige, which does not agree with my bottle (it's white, same as the Quick and Thick). I haven't yet been able to verify if Quick and Thick dries more transparently; I suppose that's possible.
And so, while they give different *descriptions* for the two glues, I'm not seeing any objective documentation that they're any different. Same catalog number lends further credence to their being the same. And in my hands-on they sure seem the same as well.