I have one of thes bloss, I love it. I have the sort where there is a separate pan and base, the pan is like a normal saucepan.
I use it mainly in the winter for stews etc. I have a timer that I plug it into, I put all the ingredients in the night before and bung in fridge, then put it on the plate in the morning and set it to come on 4 or 5 hours before I want it. Come home to lovely smelling house and no cooking!
One warning, it does tend to make the sauce rather thin so make sure you over-thicken it to start with.