Do you want manual control over brew strength? Although the strength of a brewed cup is largely dependent on the coffee itself, some models do allow users to manually adjust the strength of each cup. Total manual operation, however, means you'll need to babysit the brewing process.
Is temperature control important? Not everyone has the same opinion about how hot coffee should be, so having the ability to adjust temperature is an important feature for some consumers. Additionally, coffee drinkers who add refrigerated creamer or milk to their joe may need to start with a hotter brew. Home-Barista.com points out that manual models offer more precise control over variables such as temperature, since users preheat the water.
Will your machine live on the counter? For most coffee drinkers, their brewer is an appliance that sees daily use. That said the machine is usually kept out on the counter for easy access. You'll want to be sure it will fit under your kitchen cabinets, so measure before you shop. Bryan Gardiner for Wired magazine says some one-cup units are "counter hogs," despite their single-cup function. If it's too tall to fit, you'll need to decide where to store it when it's not in use. Manual coffee makers, such as the Mypressi Twist V2, are easily stored in drawers.
What are the necessary accessories? Both manual and automatic drip one-cup coffee makers need coffee grounds and a filter. As Good Housekeeping magazine's Sharon Franke points out, manual coffee makers also require preheated water, so you'll need access to a pan and a stove; manual machines therefore aren't the best choice for office use.
Do you want to go eco-friendly? Pod coffee containers packaged in biodegradable paper filters are more environmentally friendly than plastic or aluminum packets, especially if you brew multiple cups a day. However, in Slate magazine, Jacob Leibenluft notes that pod coffee makers also generate more waste than automatic-drip machines.
One of the biggest downsides noted for one-cup pod coffee makers is the ongoing expense of purchasing pods, which tend to cost more per cup than grinding beans or purchasing pre-ground coffee for an automatic drip machine. However, users can save by purchasing bulk coffee pods from online vendors, such as CoffeeforLess.com. Bulk orders are also available through Green Mountain Coffee directly; the company carries the majority of K-Cup products for Keurig brewers.