I have used a Thermos-branded one for a number of years. I purchased it from a site in Canada, but the packaging and documentation were Japanese. I use it primarily for camping meals in my VW Westy; I cook it on the stove, eat a portion, and put the rest in the cooker for later. I have had meals that were still pleasantly warm up to 17 hours in the cooker. Another use is potlucks; I use it just about every time. I often get questions about it.
I was surprised to learn they do not sell well in the states, until I realized that we can get a cheap slow cooker for $30 at any department store, and generally have access to reliable electricity everywhere.
