I'd actually give this a 4.5. I found it intriguing and hard to put down. It was different from many books I've read recently.
This is an alternative history where dragons are a part of the military and have a long tradition of bonding with their 'aviators' and fighting international skirmishes.
I won't go into much detail because it's laid out so nicely in the book it's a joy to read it fresh. I will say that this takes place during the Napoleonic wars and it's set in England. It isn't romance, although the characters are not eunuchs. It's just not about that.
The dragons are cool and Novik includes some sketches at the end of the book to give the reader an idea of what the dragons they've been reading about look like. But, even without that, I'd recommend this series to those who like fantasy and alternate history tales. It's extremely well written.
I got this as a Kindle freebie, but I don't know if it's available like that anymore. I will be continuing the series, though, because the prices don't seem too bad. They could be lower on Kindle, but it's better than many of the others. I've already bought the next book and I'm looking forward to it cropping up in the rotation. :D