I bought one last week as a late Christmas present to myself. I forget the brand, but it was one of the "as seen on TV" ones.
It. Is. Fantastic.
I bought it primarily to hard boil farm fresh eggs. Seems silly, but if you've ever tried to boil and peel really fresh eggs you'll know its basically impossible without massacring the whites. So day once I boiled a batch of eggs. They were a few days old and peeled perfect, but were overcooked. I later adjusted the time and ended up with absolutely perfect cooked eggs and the easiest to peel I've ever encountered.
I made a batch of chili starting with half frozen stew meat. It went from an idea in my head to me eating a bowl in less than an hour. Usually I would do it in the crock pot all day or on the stove top for several hours. The meat was tender, the flavors were good, although they did improve over night in the fridge. Thats true of most anything though.
2 nights ago I made beef stew. Used a 3lb roast and cooked it for 30mins, followed by cooking the potatoes and carrots for another 15 minutes. Came out perfect and accidentally found a new favorite recipe in the process.
This weekend I'm cooking a chicken in it, then making stock out of the carcass, then canning the stock. I have medium hopes for the actual chicken, but very high hopes for the stock and canning process.