Try that one in Shetland where the sunlight isn't really usable October-March. But this time of year it hardly gets dark. Fishinfool will remember this from Alaska - the winters can be tough.
I think idealy I would switch hemispheres to avoid the winter If I could, I would like living in the far north if I didn't have to be their in the winter.
I've had a Phillips "SAD" lamp for a long time, I've never been entierly convinced it works, but it certainly does no harm.
I really hate dark rainy days during the winter when it dosen't even bother to get properly light before it goes dark again.