I'm going to start by saying that I enjoyed this much more than The Sorcerer's Stone. Can't quite put my finger on it--maybe it was more polished, or maybe just because I wasn't aware of as many of the side details. 
 As I mentioned before, JKR has a great sense of humor. She drops in all sorts of little "blink and you miss it" moments. Some of the humor, of course, is the direct result of the unreliable narration that is 12-year old Harry Potter. (See the perception of Percy Weasley's actions throughout this book). 
 (Side note, I love Percy. He's a great character. Really, all of the Weasleys have their good points.) 
 I will say, Dumbledore now creeps me out even more. There wasn't even an "are you ok?" at the end of it. (McGonagall was obviously concerned and shocked, but she didn't get to say much). Follow that up with the "you have demonstrated great loyalty to me" talk, and... *shudder* 
 In the same vein, I'm also still frustrated with the lack of proper consequences for these kids actions. I did not walk into this series expecting to feel *any* sympathy for Severus Snape, and yet I constantly find myself thinking in the vein of, "well, you're not exactly wrong...." 
 It makes for a great story, though. I'll grant you that.