Deathly Hallows Part 1 is slow-paced but depicts the book pretty-well. But most parts are very well-done. In fact, its only real flaw is its slow-paced and dragging story but for the book lovers, it's a great movie, this flaw is comprehensible in their eyes.
Part 2 is kinda the opposite - thrilling, visually exceptional and remains loyal to the book till the last 30 minutes where it modifies many scenes to appeal more to movie-generation. I prefer the book approach of the climax but both are definitely worth a watch. Movie-wise, it's one of the best of the series though not my fav.
Also, I don't know if you'll still be able to view it in 3D but if you get the choice, then go for 3D. The movie only gets much more enticing to that.