I have the "bunny boots" and a nice pair of Sorrels.
For stationary activities like ice fishing/ stand hunting or snowmobile/atv, they can't be beat.
Problem is they don't vent moisture well and are heavy for physical type activities.

I wanted something I could wear in a off-trail type cross-country ski or snowshoeing or a winters hike.
I've done a lot of research about the traditional winter wear the Inuit's wear or modern equivalents.
A good tightly woven Anorak and Mukluks seem to be the best choice in below freezing temps for all but prolonged stationary activities in extreme cold.

A pair of real Mukluks are very expensive and don't work well if you get into wet slushy conditions. I thought the N-1B with its rubber bottom and canvas upper was a good modern alternative to the classic one, at a price that's hard to beat.

So far I am very happy and walking in them, is like wearing a pair of hiking boots, a real pleasure.