Read quite a few reviews about this novel, so this is mine:
First things first, it is an "R-18" rated novel, with the word "Harem" in it's title. What does that mean? It means "SEX SCENES"!!
If you not like them in general or does not like them in a Harry Potter fan-fic, you will probably find this novel displeasing. But, the author has made everything possible to warn you what this novel is about, so if you read it, you will have no right to come back and complain about it being "vulgar" (to put it nicely).
Now as for the novel itself:
-the writing was terrible in the past, but some good editing has done the trick for this novel and it is now actually quite good.
-the updates are somewhat stable, about 5~6/week, but there were periods of time with no updates (about 2 to 5 days)
-the story is no good. Nothing really original and it is just the mc using the System to become rich and powerful and get more women, etc, etc...
And there is no indication to show that there is going to be an explanation of why the System exist, where it came from and what is it's purpose. Just the standard typical system framework we all know and love(?).
-the characters are quite tricky to judge.
They can be said to be the same with the story: typical for the genre and nothing really original (mc strong, smart and with big penis/ women beautiful, smart, horny).
BUT, so far, the characters that show up in the original Harry Potter keep most of their original features but we are shown a different side of them here. Yes, it is a more horny and shameful side (especially for the women) but I personally like that about this novel. I mean seeing characters that I already know and love (or hate) in an entirely different view.
-the world background is EXCELLENT! It is the reason I like this novel, really. The author has done a very good job into explaining the world of Harry Potter in a scale far beyond Hogwarts.
The original Harry Potter series is, in my eyes, one long school arc, with a few out-school scenes and events, with only the last book being outside of Hogwarts, but the final showdown still happened there!!
What about the other schools of magic, the wizard communities outside of England, the political struggles in the worldwide wizardly world? We are given only small glimpses of those and I find it a shame.
This novel has already shown a wider scope of the world of wizards in the UN and the US, and refers to schools other than Hogwards.
Overall, it is a standard system/harem story you might expect it to be, but what makes this novel special to me is that it gives me the chance to read about the parts of the wizardly world that were left out in the original series.