Rozen just helped a bro in need out, even if that means making him a doll-fetishist.>>4354840
If you want to watch the series, either watch it in the order released as the reboot is more of a sequel based on the second manga than the original two that are loosely based on the first manga.
That means, Original, Träumend, Ouvertüre, Zurückspulen in that order.
The reboot anime is very good for a more serious tone., but does not make much sense without the previous series. You may also want to read the manga. Peach pit is, I think a very competent Manga artist duo able to tell a story over the Manga medium through Story and even, without words, through the layout of their pages, so reading the Manga is worth it.