First and foremost, I am dyslexic, so I use text to speech to listen to Chapters, with that out of the way, here is my review.
Writing Quality: So far as I can hear, while listening to the chapter, there are no grammar issues, so five stars for that. (It's quite easy to hear if there are grammar issues.)
Stability of Updates: He uploads two chapters a day, and it's stable so far, (Chapter 36) so five stars as well.
Story Development: It's the best Naruto fanfiction I've listen to so far, though the story development is slow paste, but never to the degree of being boring, and the main character doesn't become OP, (At this point in the story) at the same time I don't feel like he's a weakling, which is very good, another thing that's good is, though the main character is a sociopath, he is not edgy, (Other than the first time he kills, he's kind of edgy there,) apart from that he's just a battle maniac, oh and the story progression is very good. for story development Five stars.
Character Design: he doesn't describe characters very much, but enough to gain a basic picture of what they look like, oh and he describes battle scenes quite well, apart from that there isn't very much else to say. Four stars,
World Background: So far as I can tell, he does a excellent job at using what's already there and expanding on it, and it sounds logical to me at least. (what he expands on) Five stars, not much else to say about this subject.
Overall Thoughts: A excellent story, definitely worth a read, one of my favorite stories so far, in my top 10 at least, that's it, can't really be bothered to write anything else.
(This took me around half an hour to write, don't know if that's long or short, whatever.)