The panoramic view of locations is far superior to RTZ's sudden 90 degree or 180 degree turns. Design decisions appear to be completely driven by Myst-imitation syndrome, rather than keeping what worked well in RTZ and improving on it. Also, while RTZ has some of the humor of the original Zorks, ZN seems to have none. I am obviously speaking about adventure games in general here, rather than the Zork universe specifically. They have their own strengths and weaknesses.
Text adventures are a medium of the mind, graphic adventures are a medium of the eyes.
It is hard to imagine that budgets of graphic adventures will ever be large enough to show everything that we were able to describe in a 100K text adventure, and therefore graphic adventure will indeed never match the depth of text adventures. Again, watch for The Space Bar. While it certainly doesn't have the depth of gameplay that Infocom text adventures have, I think it will come closer than any graphic adventure ever has. For someone of similar inclination, I would think it would be a rewarding and challenging proposition. In all honesty, I have more fire in the belly for this sort of thing than I do for IF at this time.