It's a book, but it's not prose. This is the script for the stage play in book form. Made it a tweak more difficult to read aloud to my family, but I did it anyway.
I enjoyed the Harry Potter books the first time I read them, way back when. And I enjoyed re-reading them to my oldest son. But I'm sort of over them now. I was pretty satisfied with the ending I got from Deathly Hallows, that little glimpse into the future. So in the same way I was reluctant to read Scarlett (the "sequel" to Gone with the Wind—and in fact I never did read it), I wasn't sure I wanted to read this one either. But I did and . . .
It was a wee bit flat to me.
Aside from the friendship between Albus and Scorpio, which felt very deep and real, the rest just didn't work for me. The retread of old stuff rather than doing anything new . . . ::shrug::
I more wanted to know about Teddy than anything else. Why can't we hear what happened to him?
For the maybe two people who haven't read it, the story involves a Time-Turner and [spoilers!] Voldemort's daughter. There's a lot of alternate universes/histories or what-have-you. Basically it's an exercise in "what if?". And while writers traffic in "what if," and that question is also more or less the root of all fan fiction, making it the actual core of a story doesn't always work. In this case, it makes the book feel like fanfic.
That said, this sounds like it would be amazing on stage from a visual perspective. I'd like to see it for that reason alone.