Personally, I thought that the fourth movie was horrible. The decision to bring Sara Paxton is because Kimberly J Brown had scheduling conflicts was an idiotic decision that should have gotten someone fired. If that wasn't bad enough, Aggie Cromwell was had a MINOR role and Sophie had almost no role at all. They only brought back four MAJOR characters from the former movies and that was Dylan, (who wasn't as funny or sarcastic as the first three movies) Gwen Cromwell,(who was much more entertaining in the first three) and Ethan(who was much different from the role in the third and had a MUCH larger role.)
I think that the decision to not put Luke the goblin in was also bad judgment because I found Luke to be a funny and interesting character, and i would have liked to see if anything would happen between him a and Marnie.
There was also talk of Kal making a comeback and I think this would have been a very good idea as he was one of my favorite characters even if he was evil.
All in all, the fourth Halloweentown movie was a disappointment and I hope that the fifth will be better!