In keeping with the OP, a bigger LOTR geek you will not find. But overall I was left with a sense of disappointment from the films.
Some incredible cinematography, unforgettable moments (charge of the Rohirrim on the Pelennor Fields, Bridge of Khazad-Dum, Black Riders in the Shire), but badly let down by a terrible script (the animated version was better!) and dire music (that **** “happy hobbit” theme leaves me with the dry bolk). Some really bad acting/direction of the inter-personal scenes makes LOTR really cringeworthy too (did anyone else just want Frodo and Sam to get a room and get on with it?). Viggo Mortensen was way too wimpy as Aragorn.
The Harry Potter films are just good fun, well done. The first couple are pretty much just for kids and Half-Blood Prince dragged a lot (really strange for a movie adaptation to break from the book by removing action sequences!) but most of them have been pretty enjoyable.