I keep going back and forth about wanting to reread Deathly Hallows before the movie comes out. Generally I wouldn’t have a doubt about rereading but I was sorely disappointed with Half-Blood Prince having just done a re-read (and at that time, also re-read Deathly Hallows because I needed resolution).
So what do you say? Do you re-read the HP books before the next film comes out generally? Have you done so in the past? But most importantly - are you doing so now? 
I am totally 100% Baltar with you on this.
I voted no. I have found that I enjoy the movies much more when I don’t have the book fresh in my mind. I re-read OotP right before watching that film and I found myself overly critical and I lost a lot of my enjoyment by nitpicking the story while watching. Since then, I always re-read the books after watching the movie. That way I have the fresh visuals from the movie in mind while reading the book and I am happier that way.
I always re-read a few months before a film comes out. I find that having the story semi-fresh in my mind helps me to enjoy the film more.
I say no because I re-read the books before Half Blood PRince and I like to read them as a block.
I agree with Baconface wholeheartedly. Same thing happened with me on OotP. But also, I think I was also more disappointed because OotP is my favorite book of the series, so I had higher expectations going in to the movie.
So, maybe it depends on whether DH is your favorite book or the series. If it is, then definitely don’t read it before the movie.
In a way, the movies for the final book I already have higher expectations anyway, because it is two movies instead of one, and therefore has a much better chance of capturing all the motifs and story that they’ve missed in HBP and OotP because of lack of time (and to be fair, the lack of knowledge since they don’t know what JKR was up to, so they couldn’t have known) - most notably, for me, was them having to edit down Snape’s arc and the elves/S.P.E.W. in HBP and OotP, because they end up being rather important in the final book. (And, I love Snape, so I want more of him! :D)
So, maybe it’s not a good idea to add even more expectations on the final 2 movies by rereading the books.
They are like potato chips, once you open the bag you can’t eat just one. Or for the books, you have to read them all from start to finish when re-reading!
Interesting resposnes - and yes DH is my favorite of the series. I like the idea of re-reading after seeing the film - particularly as it’s only the first part.
I’ll give the series another read after the final movie because like many if it’s a series then you have to begin at book one and not cherry pick, well I have to anyway:)
Looking forward to the final two movies though after the let down that was the Half Blood Prince adaptation although in hindsight the book wasn’t the highlight of the series.
HBP definitely isn’t as strong as I’d like. Jim Broadbent really jsut about saves the movie from being dour and downcast the entire time. I know he’s a brilliant actor, but he is the lone bright spot of humor the entire time.
And while SPEW really isn’t something I miss, I do feel like the films short-changed Snape a bit.
My favorite book is probably the first because it’s clever and whimsical. It feels almost Gaimain-esque in its cheeky tone.
The best movie, for me, is Goblet of Fire (and this is before we all wanted “R Patz” to die). I felt like it took the most action-packed book and really made it sing, while also still finishing on a very dramatic note.
I am going to watch the first part, then re-read book # 7. I agree, there are so many wonderful details and nuances in the book, that it is hard to re-read and then see the movie.
I am glad to see this movie is in 2 installments however. I was a little disappointed in the movie adaptation of HBP- I thought it was the weakest of all the movies so far. I really enjoyed that book, so maybe that is why I did not care for the movie as much.