I too was slightly bothered that it was another "Plankton steals the recipe" plot, but as there were only a few scenes actually showing this, and a lot more focus on the sled race (as opposed to an episode like Great Patty Caper where Plankton is around all the time), I didn't mind that much. I liked that all the main characters had a decent part to play.
I also got a kick out of the claymation Snow Mollusk, but then, I've always had a soft spot for claymation so maybe that's slightly biased of me. :P
Overall, I really enjoyed this special. It was funny, quirky, and liked the fact that certain things made it unique, such as the claymation and Twitter tie-in.