I'm also a huge potter fan, and I'd say it does a fairly good job of putting you in the world but it is not a "Hogwarts simulator" it plays very much like an extended movie in that although the game world is open and you can choose what to do and there is plenty of freedom to explore and faff around in there is a pretty linear plot going on, which has actually been pretty good so far worthy of the series at least, it's clear they have a story to tell.
Yeah it's a shame Quidditch isn't in there and there could be some more things a little more interactive and practice/skill based, for instance potion making could be more involved and not just "interact with cauldron, choose potion and wait some time" you could stir it with an analogue stick with smoother and more consistent motion providing better results, timed adding of ingredients, prepping ingredients (cutting, crushing, pealing etc.).
I personally would have also put in a mastery system for spells where after learning it it is weak and perhaps fails sometimes and the more you use a certain spell the better/more reliable it's effects become over time, there could also be some fun little "time waster" activities like gobstones, wizard chess etc.
Overall though I'd say it is worth playing and it is very nice to see a good single player story driven game that works well after EA announced a couple years back that they think these type of games have had their day and are now dead.
