Playscripts as a rule are not spectacular big sellers. And as far as I can tell, the script of this is the best selling script since records began - this despite significant chunks of the fanbase criticising it as "bad fanfic". Never the less it's not stopped the show playing to full houses at reasonably high prices for about a year, so as a Potter Fanboy and the partner of a Potter Fanboy, this was squished into the visit.
And honestly, this is pretty well executed. A continuation rather than another interpretation of the saga, this picks up pretty well directly from the "22 years later" epilogue of the last book, with the children of the series protagonists about to go off to the magic school Hogwarts. But a combination of unfinished business from the series and ongoing tensions between Harry and his son lead to fresh dangers that will see all kinds of wild adventures, both revisiting favourite elements of the series and expanding the saga. It does require a reasonable amount of foreknowledge of the saga but if you haven't read the books or watched the films, why on earth are you starting with this one? And yes, despite Harry being now in his 40s, there is still a little too much of the angst elements that felt a bit laboured in the books and remain just as laboured here.
In production it's as smooth, stylish and fascinating as you probably could wish. Transitions from location to location are instantaneous and presented with wit and whimsy - sets are just abstracted enough to let the audience do some creative work while the magic is suitably impressive and "how the hell did they do that". Some of the acting is a little broad, perhaps, but it never breaks the style. Imogen Heap's music is perhaps a bit of a disappointment - I'm a fan of her and therefore was disappointed that I could recognise a lot of themes from her album "Speak for yourself" - and there are a couple of coreographed montages that kinda tend to look like dance for dance's sake rather than something that fits with the rest of the world of the show (although a movement section among the moving stairs of Hogwarts is a highlight).
I can't claim this is a deep and thoughtful show - it is, ultimately, a brand extension, but as a brand extension it's a quite enjoyable one, with a consistently rolling plot (one of JK Rowling's best features) and a suitably large amount of spectacle. Well worth the time.