I did watch Houkago no Pleiades. Apparently it's just 4 episodes, each approximately 5 minutes long. (A reasonable YouTube format, I guess.) There is a fansub version out that has them all as a single video.

I like the character designs a lot, and the animation has some of that Gainax flare. The show reminds me a little of This Ugly Yet Beautiful World, except that it is a magic girl show. (It also reminds me strongly of the Magic Users Club, by far the best magic girl show I've seen, mainly because it isn't really a magic girl show.)

Anyway, of necessity everything is highly compressed. But you should check it out.