I am somewhat disappointed. There be spoilers below!
1. Huge gaps in the story---i.e. I would have loved to read about Peeta's rescue from the Capital. I agree. However, it would have been just more battle scenes played out.
2. Hated that Peeta's personality was sucked out of him---even if he did regain much of it, I felt the character was somewhat ruined. Actually, I thought it brought Peeta to an entire new level. He isn't always the "nice" one. He, too, is vulnerable and angry. I thought this was a great use of the characters. If they had rescued Peeta from the Capitol and now he was just a rebel fighter like the rest, he would have had zero depth.
3. Gale disappearing at the end. How tidy. I cannot imagine Gale taking an important job and moving on just like that. Very uncharacteristic and seemed like a lame attempt to get him out of the picture. I disagree. Gale has always wanted to run away. As much as he was filled with anger and a desire for vengeance, his first thought was to flee with Katniss into the wilderness. Since he knew Katniss could never be his (because of the bomb that killed Prim) he had to live a life somewhere away from her. Perfect sense.
4. Felt the whole thing was rushed. The book could have been much longer.