Yeah the Alan Dean Foster novelisation had a more metaphysical ending, where Holland, Pizer, Kate and VINCENT were combined into this galactic consciousness. Don't know how that could be filmed though! The heaven/hell thing I just saw as Kate's mind "making up" something it just couldn't comprehend. A bit like the Q continuum in Deathwish, it doesn't literally look like that. Of course then there's Doctor Reinhart!