First of all, if you don't like the anti-hero style of protagonist (and now i mean actual anti-hero, now the japanese version of it showing up in media which usually gets exported to the west which frankly very much isn't), wherein the protagonist behaves in ways often considered "bad" for no sake other then to benefit himself, i would well and truly not read this LN. The protagonist is quite often selfish for no reason other then to maximize his own benefit from a situation.
Now first of all, for my own opinion on the comments on the LN being pedophilic, him being portrayed as intelligent but not acting it, and him being a "douche" so to speak (which many have mentioned).
- Whilst his little group consists of essentially always little girls (with the one guy added in every time as well except for the MC), there's no innuendo, no sexualization of their relationship in any way, and frankly the most romantic notion being mentioned in the LN is just it sometimes hinting at 1-2 of them having a crush on him, and all of this is way more then a giant majority of LNs
2/3. Saying he acts like a douche and saying he doesn't act intelligently is nearly exclusive in the context of this LN, as it is utterly and repeatedly expressed both outright, and hinted at, that most of his acts are simply to maximize his own gain from an encounter, or simply because he doesn't want to. He might not follow the absolutely ridiculous notion of intelligence that japanese media tends to subscribe to with the "sherlock holmes"esque deduction and flawless month long plans, but he sure as hell is intelligent, he can bend essentially every situation he's in to the most profitable one possible result for himself, and due to the fact that his behavior is a result of him essentially ignoring his emotions and being as profitable as possible in a world where that's mercenary, saying that he's selfish whilst still saying he's not intelligent is really really odd.
Overall i found it to be an excellent piece of writing, it had a good enough story but what i really enjoyed was the protagonist, he's a true mercenary (except possibly for the fact he almost always tries to make sure a deal he makes with someone be as profitable as possible for them as well) and apologizes in no way for it, i found the much more realistic depiction of what you would need to do to survive in an alternate world delightful (on a few occasions he chooses not to help people because he knows they have something he needs until they give it to him, and doesnt just rush in "Because we must help them!"), and i absolutely loved the fact that the only reason he's involved in the "main story" of the world itself, is because one of the key figures involved in it had something he wanted and traded it in exchange for assistance. In summary, a story driven by the protagonist who's a selfish pragmatist and feels no need to apologize for it, and makes a story based on a premise that's used quite alot impressively different from the piles and piles of tiny variations of the same bland premise and same bland protagonist.
P.S I'm on chapter 190 which is as of this posting the current chapter of the story (translated that is), and please post chapter if you do a review, without a note where you are your review is utterly useless and can be outright harmful