My girlfriend and I caught this series on 'Tech TV' during a Sunday marathon. We were drawn to the compelling story line, Intelligent characters and fantastic visuals. We were so drawn that we went out and found it on DVD at a good video store so we could watch it again.
It does bear a passing resemblance to "Castle in the Clouds", but with a more 'grown-up' sensibility. It's a shame episodes 14 through 26 will not be available to be shown on TV until next year, it's going to be a long wait.
Tech TV has previews of the various episodes if you want to take a closer look.
Update: Saw the last 13 episodes, and the pace of the series grows more relentless until the tension is almost unbearable for the last four episodes. Excellent story arc, and some very affecting tragedy at the end. Strongly recommended to any interested in a good story, strong characters, and inheritable visuals should check this series out.