I also read Quag Keep (1979) because it was a D&D crossover and I loved D&D. Sadly, I did not love that book, It's not that I had anything against the book, but I just didn't have anything for it. Whatever it was that captured a reader's attention, it didn't capture mine. The only thing that I remember about it were the bracelets with dice inside them that spun about on occasions. I am happy to say that D&D literature has come a long way since then, but sad to say that doing better than Quag Keep was pretty easy.
As Norton was such a dominant name in the 70's, I will eventually need to read her as I reread the greatest fantasy hits of that decade. I don't look forward to it. I rather suspect that her sensibilities and mine do not match.