"Great book... but why the changes?"
I've read 'His Dark Materials' trilogy in print and bought the audiobooks so I could listen and knit at the same time. It's great to hear Pullman's narration and the voice actors playing the characters are really good.
Just one complaint: why the Americanisations? Pullman did not write 'sidewalk' and 'traffic circle', he wrote 'pavement' and 'roundabout'. A minor but very annoying point.