An alternative is to purchase a removable turntable or buy an oven with a turntable that can be turned off, so you can fit a larger dish in the cavity. You can also periodically turn the dish yourself. Precision timing is important when microwave cooking, and electronic touch controls provide greater accuracy than rotary dials. Most electronic controls also allow the user to program the oven to defrost and then cook automatically, or to change power levels for multi-stage cooking. Auto-start allows you to program cooking hours in advance, but, in actuality, you would not want your food to sit in the microwave cavity for several hours prior to cooking.
Power levels are percentages of the unit's total cooking wattage.
Four or five power levels are adequate for most recipes, and two will do for defrosting, reheating, and quick cooking. Probes and sensors prevent over-cooking by either stopping the oven when food is done or shifting to a keep warm cycle. The user needs to insert the probe into the meat, casseroles, or stews to monitor the food. Sensors are built-in to the microwave. Browning units act like a broiler.