I just finished reading the first volume. It’s ok, but I didn’t enjoy it as much as Sunstone - the leads and their relationship aren’t fleshed out as well, so the book feels a little bit hollow (especially in the early stages where it more or less ticks off the story of them getting together in bullet-points). It’s also quite short - there’s only about 80 story pages in the first volume, and it ends just as things are starting to get going.
That said, it has the potential to be interesting now that the setup is out of the way, and I grew to like the characters more in the second half of the book as their relationship gets a bit more complex. Plus, the art is quite nice (although there’s nothing as good as the fully-rendered sections of Sunstone).