Nice side stories, but I would only recommend reading the first one, which is Annie centric (unless you hate her character lol). The Mikasa one felt like a big waste of time, since It was pretty much pointless and even kinda ooc.
...yes i know that too~ i was so excited for it, >﹏<
but yeah, i think there's an adaptation, an OVA or Specials if the last time i checked were right... i was kinda curious so i search for the Anime yet hadn't found it, ( ಠ ͜ʖಠ)