Went on Sunday and here's what I thought.
First thing -- EVERYTHING is decorated in the park. A minor sign with penguins has them decked out in Santa hats and scarves. Garland and ornaments and lights are everywhere. The counter-service restaurant we ate at had a Christmas tree inside, garland and decorations around the room. Christmas music played everywhere. We saw two separate groups of live entertainment with musicians playing carols. S'mores and hot chocolate for sale. And then there's the shows...
We saw:
-The Polar Express overlay -- I think the film in the simulator is lifted directly from the Polar Express movie. But considering I don't like Wild Arctic very much, I thought this was a nice treat. The preshow that sets up the simluator has a nice steam effect that goes the extra mile. The simulator doors are themed to the train. Tree branches hang over the loading area.
-The Clyde and Seymour Christmas Show -- that mime who does the preshow for all the Clyde and Seymour shows is one of the best entertainers I've ever seen in a theme park. Guy deserves every penny he gets. And the main show was funny, Muppet-style humor.
-The Sea of Trees show -- liked this a lot. The trees use LED lights, I guess, that can change colors, produce different designs.
-Winter Wonderland -- ice-skating show that was fantastic. Some very talented skaters here. The guy swinging the girl in the finale, with her head inches away from the ice. The crowd audibly gasped and then errupted in applause and a standing ovation.
-Fireworks show -- had fireworks, water fountains, and the lighted trees working in sync. Compared favorably to Illuminations, I thought.
Overall, if I was going to go to a park for Christmas festivities, I think SW would be my choice. Candlelight at Epcot is always nice, but a pain to see because of the crowds. Lights at DHS is impressive, but it's not something that takes hours to see. SW definitely offers more.