There are two very different types of margarita machine. The first is the large commercial units you would see behind the bar at your favorite watering hole, Mexican restaurant, or beach resort. The second version are those models made for the home user, such as the Jimmy Buffet line of products. They work a bit differently but yield the same high quality drinks.
The commercial units are quite easy to use. They are based on super cooling your drink mixture, while keeping it spinning to avoid freezing solid. Many people think they are hooked up to a water line. In some cases this may be true, however many models don’t need anything but the mix and a fair portion of alcohol. The mix is pre-blended to give just the right consistency when the cooling of the machine is applied. This makes for a very smooth and enjoyable drink as no ice has to be crushed in order to make it.
The home versions work quite differently. You may find a cheap frozen drink maker that is nothing more than a kitchen blender in different packaging. But if you buy one of the nicer models, like the Margaritaville products, you will find that they operate much differently. A home margarita machine usually has a two stage motor system to crush and blend the ice separately. This enables the machines to produce similar quality drinks to that of the more expensive commercial units.
First the ice is shaved in the initial stage by a dedicated motor and blade system. This deposits a fine grade of ice into the pitcher that is then easily blended for a smooth drink by a second stage motor and blade. It is like having two machines built into one. I think you’ll find that the quality and consistency of drinks that it produces is well on par to that which you get in your favorite restaurant.
Though the two types of margarita machines work in slightly different ways, the quality of the drinks seem to be on the same level.