I did enjoy this book, BUT...
The Sapphire Rose is a classic fantasy tale with heroic knights, evil villains and a Queen who knows her own mind. The good guys win and the bad guys lose... too easily - and that is why I've only given it 3 stars - the good guys face a challenge... and overcome it far too quickly, whilst observing that when one does "action A" we find that people usually opt for "response B". There were no moments where I felt concerned that things were going to go seriously wrong, hence I was never on the edge of my seat. For 99% of the book, the heroes seemed to hardly break a sweat (except for the one moment where it felt that something tragic had to be there).
My other gripe is what I call the AI ending (the last 3/4 hour of the AI film where I wanted to gnaw my arm off). Just when you think the story is done (our hero returns...), it is not. I thought the last chapter was pointless - "everyone is a bit down, but luckily the Goddess saves the day!".
This is the third and final book of the Elenium and worth reading to see the adventure through to the end, but I think when it is over, you might be left feeling a little disappointed.