I enjoyed this series. It's one of the better fantasy series I've read in a while. I thought the characters were easy enough to feel close to and like. I liked the dash of mystery that was thrown in, along with the underlying sci-fi element.
Some things I didn't care for much:
We started out this journey with Erde and her dragon Earth. However, we don't really stick with them very long. After the first book, Erde and Earth are shoved to the back burner pretty quickly in place of N'Doch and his dragon Water, who then seem to dominate the rest of the series as main players. In fact, as time went on, I even started to feel annoyed by Erde. Instead of being the voice of reason, which it seemed like that was what was being aimed for, she started coming off as whiny and impatient. Too much like a spoiled child. I realize she WAS something of a spoiled child, since she was royalty, but she didn't do any growing up until closer to the middle or end of the last book. I was disappointed by that.
I also didn't care for the way the writing would switch from the traditional third person or past tense style to something more "present". While it was a very interesting take on the perspective of the characters and where they were in the world's history (Erde in the year 913, N'Noch in the year 2013, for example), it was distracting and took a lot of getting used to before it didn't slow down the reading pace. I think it would have been better to leave it in the traditional third person style the whole time, personally.
Unanswered questions. This series has an element of mystery to it, and that's not bad. I like having to read on to the end to find out what something mentioned earlier on was really about. But what I don't like is when I wait and wait and expect to learn something valuable about an important part of the story, but then the explanation is never granted. The 4th book suffered from that far more than the others, though. In a way, I wonder if it wasn't that the author had gotten bored of the story by the time the last book was being written, and she hurried the ending along and just forgot that she had unanswered, yet apparently important questions and information left behind.
The ending. I won't, of course, spoil it for anyone. As I said, though, I think the author must have gotten bored near the end, because I think it should have ended with a bigger bang than that. Even so, the journey getting there was worth the disappointment, so I won't complain about it too much.
Nothing really BAD ever happens to our heroes. They see a lot of destruction and misery, but there aren't a lot of losses, really. In that way, just because of the way things in this book work, I felt that made it lacking. Nobody ever has to suffer much for deep loss, and if it seems like you think they SHOULD be suffering the losses they do encounter more, they don't. Many a broken heart seems to get forgotten about just a chapter or two later, and the character doesn't act as truly human about it as we might expect of them. Losses, for as few as there seem to be, come off as simple plot devices that are only brought up again when it's convenient.
Childish writing. Sometimes, it felt like the writing was too convenient or the characters too sure of themselves, like you might see from someone less experienced. Maybe in a child or teenager's fiction writing. The behavior of some of the characters reminded me a lot of an old friend of mine's writing. But, he was 15 at the time...
Slang. Now, this is more of a personal gripe, so I don't expect anyone to decide to read or not read the book based on anything I say here. I just got really annoyed with how N'Doch would refer to movies, television programs, or what sound a bit like general YouTube videos as "vids". Even though these books were written in the earlier and middle 2000's, I can't see how the author might have expected that people in the year 2013, which wasn't that far away from when the first book was published, would be calling these things "vids" by now. Since, in reality, we're on the doorstep of the year 2013, and nobody calls them that to my knowledge.
Okay, I know it seems like I'm saying a lot of negative things about the series, but I do honestly feel there is more good about this series than bad.
I liked the time travel and the different takes on what various time periods would be like, especially if the world was going haywire. In fact, the picture the author paints of our future is scary BECAUSE it could become a very true reality if mankind doesn't clean up its act. The year 2013 in reality isn't quite so filthy as the one depicted in the books, but it could be. It's probably not that far off from what the author envisioned, in all truth.
Things don't always work out the way we want, and that's good. Life isn't about always getting things your way or always having a happy ending, so to speak. When things didn't always go the way the characters wanted or expected them to, or even as cliche would demand, I felt that made everything feel more real.
Overall, I think this series is worth at least one read through.