The LMB light kit for the Winter Holiday Train is an excellent addition to what is already a great train set.
If you thought that the train build itself was already colourful, wait until you add the lights - it takes it to a whole new level!
The bright light at the front of the train lights the way down the tracks, the flashing flights down the sides and up the tree add so much visual flair that the video preview doesn't do it justice - you really have to see it in the flesh.
The nature of wired lights unfortunately means that you will need to disable the spinning tree so that it stands still, and I'd have liked to see some more lights added to the engine as well (eg: a bit light inside the cabin for the driver at least), but overall it's an excellent kit.
Note that at the time of writing, LMB do not yet have a solution for running this kit with the newer Powered Up motors. This kit currently only works with the Power Functions motors (a future upgrade would entail replacing the power-in lead only, so you wouldn't have to replace your entire kit, and there's nothing stopping you from using a traditional separate battery pack hidden somewhere instead either).
Note also that the kit does not include instructions - you must refer to the installation guides on the LMB website. The instructions are clear and easy to follow.
The lights are cool to the touch and you have no fear of leaving them on for several hours straight.
Overall, highly recommended!