Love this kit! The lights add so much to this already quirky and delightful model.
Photos of this model on LMB's site do not do this kit justice. When you see the pink LED lights in action yourself, it really makes the model pop. You wouldn't think pink against brown would work, but it does.
The fireplace and candles showcase the FX board nicely and add more mood to the model.
Installing the kit was pretty simple and straight-forward. The difficult parts were the lights for the roof sections. the LMB instruction will have you pull away the roof areas, but I highly recommend that you remove the blue Technic pins holding each roof apex together as well as it will make it that much easier to re-assemble after you've hidden away the cabling. Next most difficult was the Christmas tree as the 1x1 studs can be hard to push on over the LED and cable.
Most of the building cable excess and the FX board are stored inside the chimney. You don't need to remove the Lego light brick either, and it still works afterwards, though there is shadowing caused by the storage of the LMB cabling inside the chimney (let's be honest, you're not using the Lego light brick anyway, are you?).
Note for the Lego purists: you will need to modify a couple of translucent flame pieces in the fireplace with a pair of scissors to allow space for the LED that illuminates them. I think this is an acceptable requirement, and you can't see the fact that you've cut them.
Overall this is a clean and tidy install…