...but I do think that the added material, specifically the songs they added (like He Lives in You, Shadowland, and especially Endless Night) are some of the best songs in the show, and powerful important moments for major character that fill it out into being a real musical rather than a cartoon with some songs.
I like the score of the show in general. But I feel that they generally stop the show cold. Taymor's staging often doesn't help (for instance, making "I Just Can't Wait To Be King" as if it's a separate show all by itself, scenically). I wanted to songs to advance the story more - I felt that for the most part they simply commented on the moment at hand. Ultimately, if I had to describe the whole experience, I might be more inclined to call it a musical pageant or a musical spectacle rather than musical theatre.
However, the creative genius that Taymor brought to the piece is to take an incredibly slight storyline and to seem to make it much more epic. Maybe too much so - but still, her vision for the piece is pretty amazing. Just that a little less of it might have gone further.