I don't really see the point in reference materials like this or Star Wars' Essential Guides when comprehensive websites like Halopedia (or Wookieepedia for Star Wars) exist and usually are more up to date.
The Essential Guides for Star Wars
aren't just rehashes of old canon; they often add new info or retcons too.
Yeah, but Wookieepedia has the same information along with way more than any other single Essential Guide. Plus it's free and constantly being updated with every new material released.