(spoilers)
I knew before I even saw this episode that it was going to be a version of A Christmas Carol, and considering that the holiday in question here would be Hearth's Warming instead of Christmas, I also knew that there would be some differences in the details.
I think the name of Starlight's character in the story was "Snowfall Frost", and I find it interesting that, like Starlight, she had intended to do something selfish without realizing just how terrible the consequences really were until she saw it all for herself, after which she decided to change her ways for the better. And amusing to me is that she was even given the same hairstyle as Starlight used to have as a subtle way of showing that she's not a nice pony (until the end).
I also liked how all the characters in the story were dressed up to reflect the 19th Century setting that you typically expect from this kind of story, both the main characters and the background characters.
Also, just before the second commercial break, Spike asked to take a break from the story to get a refill of hot cocoa. I think that might be the only moment in the entire series so far where something even close to a fourth wall break regarding commercials was made.
Overall, it was definitely another good holiday episode.
(end spoilers)