This is a fun show with a great story, wrapped in a stylish retro theme.
At first this show may appear to be episodic in nature, but a larger narrative is slowly introduced and completely fleshed out by the end. It's a tale of espionage in a world where the Cold War never ended, so naturally there's plenty of cloak and dagger stuff, but it also explores some unexpected themes. Considering the original manga was written in 1967, this was really ahead of its time.
The central character, Mylene, is fantastic. She manages to be cold and ruthless, kind and delicate, sultry and provocative, and much more - and it all seems completely natural. Other characters have a charm all their own, even if they're only in one episode. It's a very likable cast.
The music has a good bit of variety including some moody jazz, haunting piano pieces, more classic compositions, and some very 60's sounding rock/pop. All executed very well.
Animation varies in quality, though it's always decent and there are plenty of instances when it's very good. Occasionally there are some very beautiful scenes (check out the sunset in episode 3). Of course, the style is all very retro which is a nice change of pace from all the other anime out there.
This is a very well done dub. Mylene's voice is simply perfect, and very sexy. Other characters are quite good too, even when given a foreign accent they sound natural and well done.