The fact is that ingredients are most accurately measured in weight rather than volume. Think about three cups of cubed potatoes: imagine how much that measurement can vary depending on how the cubes are cut and packed. While your hash browns might not suffer for lack of accuracy, baking is another matter. How a cup of flour is measured is measured can be the difference between a fallen, but not collapsed soufflé, for example.
If you like speed, you'll enjoy the way a scale allows you to just dump ingredients into a bowl until the magic number is reached. No swiping with a knife to level a cup of sugar, or eye-balling a cube of butter to make sure you slice along the tablespoon marker correctly.
Of course, for regular old run-of-the-mill cooking, you don't need a scale. You know we're not in the business here of telling you to buy pricey gadgets. However, if you use old recipes, use foreign recipes, develop recipes, adapt recipes, or have reason to make a recipe many times and need the product to be the same each time (like Faith's wedding cakes, for example), a scale can be anywhere from helpful to absolutely essential.
There are two commonly used types of scales: mechanical and digital.
Since I work in two kitchens, I have two scales. Both are small, digital, and made by Salter. The reason I like digital is because they are light and very accurate and they give a reading almost instantly. Most come with a tare feature which lets you add your own container then zero-out the reading so that you can measure, say, a bowlful of sugar or flour without having to subtract the weight of the bowl yourself.
• Buy the Square Stainless Steel Electronic Kitchen Scale (model #1004) by Slater (Amazon, $38.95)
• Buy the Round Stainless Steel Electronic Kitchen Scale (model #1015) by Salter (Amazon, $24.95)