Neither one nor the other: why oppose fictitious inspiration and travel guides as if they were separate entities?
It's a false dichotomy that ignores the intrinsic narrative power of a good guide.
A well-written guide is a work in itself, with its own story, characters (places, locals), and stakes, capable of arousing the desire to travel just as much as a novel.
It's not an appendix to fiction, but a form of fiction that already immerses you in the travel experience.
Take hiking guides that, with evocative descriptions and local anecdotes, create anticipation and a desire for adventure, long before any film or book.