The whole series is very enjoyable. There are a few typos throughout, which is why I'm giving it 4 stars.
The plot is entertaining and the explanation of the technology involved leaves enough mystery that you can't tell where this is going to go.
The world is a nice steampunk-ish setting, and the characters are definitely interesting. The ancient "magical" power concept has a lot of potential to be fleshed out in future books.
Michael's internal monologue give him a bit more characterization, but he still often seems like a bit of a one-dimensional Victorian male hero stock character.