Wouldn't be without it, an essential part of our cooking regime.
Mainly used to heat the contents of tins (beans, spaghetti, so on), done in around 3 1/2 minutes, and often in the bowl they'll be eaten out of, so less washing up!
Also used for heating frozen veg (we have a sort of 3-part steamer contraption that goes into the microwave), and occasionally for reheating liquids like cold coffee.
It's so simple even Ossie uses it (our oven cooker knobs are waaaay too complicated ....)
It does have some fancy settings, including one called "Chaos Defrost" which sounds vaguely sinister, but like Kaz we tend to defrost stuff overnight. We just use it as a basic piece of equipment.
It'll shortly be used to heat up the mulled wine (20 seconds!)