When it first came out, I loved it. Absolutely LOVED it. I even copied out the whole 'I am the Ancient, I am the Land. My beginnings are lost in the darkness of the past,' piece into one of my school exercise books.
The isometric maps were a joy. There was something truly evocative about them, especially the towers that went up level after level (and which I wanted a PC to fall down) and I think the 'pulsing red glass heart' in the Guardian of Sorrow has to be one of my top five rooms ever for sheer atmosphere.
But like many others here, I can't really forgive the tombstone humour (Americo Standardski, Inventor?) and I didn't really like the suggested random rearrangement of plot elements. I'd have preferred a single solid story to that tarot card business.