This one is a 9/10.
But, like, maybe wait until there's more than 20 chapters before jumping in.
I've read the original fanfic, which is probably still available online, and it was actually pretty great.
Some really funny stuff, some cringe stuff, some pieces of philosophy that genuinely made me think.
(The author's basic reason to write this is to make the reader think about rationalist philosophy, so... mission accomplished.)
I don't read much fanfic because I want it to be as good as the original or better. This story definitely qualified for that IMO.
Basically, this is Harry Potter if most people had, like, 50 extra IQ points.
Harry isn't basically a jock, he's looking to be a scientist in the field of magic.
Voldemort isn't basically a power-crazed madman like in the original, he has an actual political philosophy.
Dumbledore is still basically a weirdo, but even more crazy-awesome.
It's a world where wizard kids learn predefined spells because magic is frickin' dangerous, especially transmutation, but it's implied adult wizards can design their own spells.
Note that the author killed off some characters, like Malfoy's mum or Dumbledore's brother, for extra wizard-war drama and to make the filial bond between Draco and Lucius stronger. Also, he's not afraid to make fun of some of Rowling's more contrived plot points, and make up better replacements.
Also also, he's definitely speed-running this thing; IIRC the story ends before the end of the first year.