I've had several different rice cookers over the years, but the best one I've had, that lasted the longest, was my 10 cup Krups rice cooker-steamer-slow cooker. It lasted close to 10 years before it started shutting off before the rice was fully cooked. I then bought a 5 cup Krups rice cooker-steamer-slow cooker-oatmeal maker. I've had it for a couple of years now and it is everything I expect from a Krups appliance. I must admit I have never used it as a slow cooker, but I have made rice in it, and steamed vegetables and dumplings, and I have even made Irish steel cut oatmeal in it.
Oh, and unless you have an extrremely large family or are cooking professionally, you are never going to make 10 cups of rice at any one time. A serving of rice is 1/2 cup cooked, and I haven't had to feed 20 people in a very long time. That's why I opted for the 5 cup machine.