I read this book about seven years ago, and when I was younger it was one of my favourites. I read this first book almost as an accident as I only found out about it, when I saw it sitting in one of my friends bags while she was taking it home again after another friend had borrowed it. I asked if I could read it as well, and just about 24 hours later I had already finished and couldn't help myself starting the second book already.
I liked the setting, the story, everything about it. I think it was the first book I read on (a sort of) time travel, but I really like it. I really enjoyed it, and needless to say: I also wished I could travel to Renaissance Italy at Night... (But like the Hogwarts letter, I'm still waiting)
Note: I read a Dutch translation of this book