Recently I watched this anime with my best friend, and we found it good, but no masterpiece.
Some beautiful characters, sometimes it looked good, sometimes it had nice Castlevania-ish music, some episodes were good...
...and sometimes it decayed a little.
Generally, I'd say it's a 6,5 or 7/10.
It started better than it procceeded, but the ending wasn't bad either. It's just that it promised to be better.
A good choice to watch something about vampires, anyway...
Anything is better than Twilight! Right?