Titles I've written about:
Sweep: Book of Shadows (2001):
Not a particularly good book, but it's attractively packaged—I do love the cheesy die-cut action—and I can see how some teens (especially Stolarz fans) might find the series addictive.
Balefire: A Chalice of Wind (2005):
Luckily, the chapter headings identify the speaker, because while the girls are different personality-wise, other than Clio's habit of using the occasional French word, their voices are pretty indistinguishable. Some readers might have trouble with the chapters that act as quick cut glimpses of the numerous secondary characters—they felt extraneous as they were happening, but by the Big Reveal at the end, I was glad they were there.
Immortal Beloved (2010):
I enjoyed this one quite a bit more than I expected I would. That sounds like faint praise, but it isn't: I REALLY didn't expect to enjoy it as much as I did. The pace was strong: The story moved right along, there was a good amount of tension due to Nastasya's new surroundings as well as the worry that her friends—or should that be "friends"?—will find her before she's ready to be found, due to the secret past she's been trying to forget for centuries, due to the passive aggressive infighting at the farmhouse, AND OF COURSE due to the sparks that fly between her and the VG (Viking God).
If you like paranormals, I'd definitely recommend that you give this series a try—Nastasya's got a great perspective (lots of flashbacks of different time periods and so on) and a snappy voice, and it's a much more thoughtful spin on immortality than you'll find in most other places.
The last third of the book feels a bit rushed, but other than that, it all works. Questions are answered, smoochies (and more!) are had, promises are made, ends are tied up, and—unlike some books that promise a battle and then totally renege on said promise *cough* Breaking Dawn *cough*—there is an actual, honest-to-god Big Battle Complete with Swords and Decapitations.