I have seen them many times over the years and have been on the North side of them as well at times.
As has been stated, waking the screaming hordes in the back is not a good idea and also not appreciated by the cabin crew.
I have always made a point of getting the boys and girls from the back to come up front to come and see them.
I also spent some time in Labrador and when you get away from light and noise they are even more wonderful, and can be heard.
A truly wonderful part of nature that we, as aviators, have the priviledge of seeing.