'I could read it myself first, but I wanted to avoid that dubious pleasure'. Give it a go, you might be pleasantly surprised. Gripping story-telling; direct, lucid writing; political and moral complexity, and more emotional depth than many adult books I've read recently - they are hugely enjoyable reads IMO.
DD1 read them when she was 10, rising 11, and loved them, as did a few of her year 6 mates. I can't see dd2 being ready for them at the same age (unless some drastic transformations occur in the very near future!). So I also have to say 'it depends on the 10 year old'.