This sequel was better than the original. The A story is an evolution of the friendship established in the first movie; how does time affect relationships?
The setup of getting into the internet is great and the first few moves within the internet advance the plot very well. The visual representation the internet is fantastic. If you were online at the turn of the century, you will get so many great references.
The use of Disney IP is incredibly awesome. The Disney princesses steal the show! Their B plot line is fantastic. I think they are the best part of the movie.
I recommend seeing this in theatres, but have no opinion on 3D. This is what a sequel should be. So far this is my leading contender for best animated movie of the year.