Well, from my tradition's perspective, there is no difference, other than a Western or Eastern perspective on the same experience. After all, we will all experience the "end of times" when we die... this is the end of the world as we know it! The title of the book is "Revelation", not "End of the World", thus this is an ongoing event, occuring all of the time, just as you point out about the Tibetan Book of the Dead. The interpretation of Revelations as a book exclusively about the end of times is a distincly ORTHODOX CHRISTIAN perspective, NOT a Gnostic perspective!

So what is the difference between the phenomena of "mind" and the phenomena of what we believe is objective "reality"? "All is mind, all mind is one" state the hermetic schools. So... this "reality" is simply a "mind state", as you say and phenomena that occurs all occurs in the "mind of the experiencer", yet we call it "real" because it is tangible by the five senses, and experiences in dream, or imagination are not, so we typically call this "less real". Except, what will experience be like when we no longer have one of these bodies? Will the intensity of these internal experiences increase as our link to the body is severed? And if we were to experience this "Revelation" in life, would this "reality" become like a dream and we like the lucid dreamer? Perhaps this alludes to what these Eastern schools are getting at when they call this world "illusory"....