But no, no spoilers.
Still, you should have read the book already.
Harry Potter and the Goblet of Fire is an unwieldy book, and they had to skin it, tan it, and make a stole out of it to get it down to a size that would fit in a 2 hour movie. There are great heaping chunks of the book that are just gone.
The pacing, on the other hand, is fabulous. If you're going to slice the book that much, you might as well give a lot of thought to pacing, and get it right. The cut from the Quidditch World Cup game to the victory celebration was really abrupt (What? Are these folks who just didn't get to the stadium yet? Nope, the game is over...) but that was the worst.
Special effects were smooth as glass, but that's to be expected.
Viktor Krum and the boys of Durmstrang look like the next crop of auditions for Bel Ami Films (if you don't get that reference, don't ask).