Hi, Dan!
I am always drawn to anything seeing the latest and greatest at Walt Disney World, so I would lean toward the new
Art of Animation Resort. Although only one section has been open a few days with more sections to follow, it is already getting rave reviews from guests. Since this resort will have its own designated buses, I really would not worry about crowds, and with several pools and a large food court, I think this beautiful resort is ready for even a large amount of guests!
All-Star Music is always a good choice as well with the choice of a standard room or family suite. You may experience sharing your bus with Movies and Sports, so be prepared for additional stops and sometimes crowded buses. At All-Star, you also have the ability to hop to Movies or Sports to use their pools or enjoy their food courts.
My final answer: If you enjoyed your stay at Pop Century last year, I would go for Art of Animation. If you want a different feel, then book All-Start Music. The great thing is you cannot go wrong with either choice as both will be amazing! Have a great stay in January at Walt Disney World!