Disposals come in an assortment of models with varying amounts of power. A top quality disposal will give you years of service with no problems. Most disposals are continuous feed models that operate with running water. These work well but are a bit dangerous. Safer models on the market include one that cannot be turned on until a stopper is placed in the sink opening. A quality machine will have one horsepower or more, while the low end models will have only about one third horsepower. The more powerful motor doesn't mean the disposal will work faster, it just means that it doesn't have to work as hard. More horsepower means more years of service. Disposals are noisy, but you can reduce the noise of your disposal by having the plumber install the disposal on a cushioned mounting bracket. And remember, disposals can't handle banana peels, cornhusks or celery.