The art is beautiful, unique, fascinating. You can approach it from many angles, it's never pedestrian or boring. There is not one weak card in the whole deck.
The intellectual, spiritual, aesthetic, esoteric, philosophical and historical value of this deck is incredibly high. There's a whole world of meaning in every card. I had my first reading with a Thoth deck in 1984, bought my own in the early 90s, and I still discover new things every time I look at it.
And in readings - it's eloquent, honest and gives you food for thought.
For me, the Thoth is in a league of its own. I have a number of decks that I like very much and value highly, and there are others I find fascinating and may wish to own one day... but the Thoth is really special. It's so RICH - in Hebrew we say, it's full like a pomegranate - full of seeds and ideas.