1

I just finished Noein last night.  I had kind of a strange relationship with it, the discs would sit in my queue for ages, I always picked something else to watch, but once I did get around to sticking in a disc of Noein, I'd watch it straight through, and if I had another disc available, I'd immediately stick that one in and watch it also.

To answer the obvious questions with minimum spoilers:

Does Yuu get a grip? Yes and No.  His role in the series is obviously to be the one that saves Haruka, and Karasu is continually telling that he must get stronger to do that.  But after the middle of the story where they give him some development, he doesn't really do much until the last episode.

Does everything get explained? Again yes and no.  By the middle of the series the situation is fully explained, and its just a matter of rolling out the events.  By the end you know what each character's motivation is (Noein is the last one you learn about, for obvious reasons) and the psuedo-science has been explained, etc.  But there are some things they dont even pretend to address, such as who is the old guy Haruka sees in the dimensions.

How is the ending?  It resolved everything important and made sense.  Not every detail is explicitly tied up on screen, but the explanations of the science and people's actions during the climax let you guess at those.  It avoided most of the bad ending modes, but does tend a bit towards dues ex machina.

Personally I liked it, but it's nowhere near the top of my favorites list.  I'll probably rewatch it at least once to pay more attention to the science and details.  Most of the characters got a suprising amount of development and detail over the series, and the story was interesting and the ending was obviously planned, not thrown together at the end, but the execution could be better.

2 That's pretty much how I felt about Noein, too. While I was watching it, I didn't want to stop. But when I wasn't watching it, I felt strong resistance to starting again.

3

Please Twins! is one of those series that suffers when you marathon it, no question.  Hearing them ask themselves the same question over and Over and OVER does a fine job of driving one bugnutty... and I LIKE the series.

Noir is another one that has that problem (note: I really like Noir, too)... I was SO hoping that someone would "accidentally" shoot that damn watch!