Let's get the cons out of the way first. The screen writers took too many liberties to change plot lines and left out important parts of the book. Leads to too many inconsistencies.
Otherwise, special effects were great, many funny scenes. The Potter gang is growing up and hormones are raging in the 6th HP film. The usual "i think I"m going to puke" faces from Ron Weasly.
My 11 year old son loved it, which is why I gave it 4 stars.