We've used the Buffalo rice cooker (with stainless steel insert) for almost a year. They claim that it can be used for a variety of functions besides rice cooking, but we have only used it for cooking rice. It is ok in terms of the rice quality and cooking time. I can't tell the difference between it and my previous Japanese rice cooker. However, to make it non-stick, it requires some techniques. After the rice is cooked, you need to wait for 15 mins before opening the pot (it will stick to the pot if you open right away). Then you scoop the edge of the rice to the middle, close the lid again and wait for a while before serving. It is not hard to clean, although it is not as easy to clean as the non-stick cooker. Occasionally, you still have soak the pot in water before cleaning when there is sticky rice residue. The good thing is you can wash your rice in the cooker without worrying about scratching the surface.
I've been using a electric pressure cooker with a stainless steel inner pot to cook rice & congee. The rice is done in 8-10 mins, congee about half an hour. Doesn't take a lots of effort to clean (soak in water than normal wash) never stick to the pot. The only problem is when the rice is done, you have to let the steam out (a bit scary for me).
My family has been using rice cooker ever since they were available. Before there was coated inner pot, all inner pot were made of steel/aluminum. We kept water in the pot overnight to remove the sticky rice at the bottom after use. It worked but it was messy.
The coated pot material is inert. It will not stay in your body even if you eat it.