Perhaps I lack sophistication but I liked it.
It's been so long since I read the book that the details were fuzzy to me but as with the other two adaptations I can live with the changes. To do faithful film versions would require making mini-series of them.
I didn't expect a high budget production and expected to see changes, partly to make sense in the allotted time and partly to appeal to a broader audience.
As for the uninitiated, I'd think that those who liked it will like the book better and those who don't probably wouldn't like the book either.
Even with all the flaws in the movies I hope to see other of T. Pratchett's books adapted to film. I'm rooting for "Night Watch" as the next one.