Design: Nespresso machines are not large by any means, but they do vary in size from one to the next. We paid close attention to the length, width, and height, as well as things like attached milk frothers and water tanks on the sides and backs of certain machines. We also noted how many used pods each machine can hold.Features: In addition to noting which line (Original Espresso or Vertuo Coffee) each machine is part of, we also considered the additional accessories and tasks of the Nespresso machines we tested. This includes things like a milk frother, digital screen, and any self-cleaning capabilities.Taste: The most important aspect of testing a coffee machine is the taste of the brew. We made several different types of drinks using two different flavored capsules on each machine and tried them (risking overcaffeination). We also measured the temperature of brewed coffee as well as the aroma and crema on top, and then rated it all on a scale of 1 to 5.Ease of Use: Another reason Nespresso is a beloved brand is because its machines take out the manual aspects of making espresso. We evaluated just how easy each machine is to use, asking questions about what buttons have to be pressed and how often the water reservoir needs to be filled. In addition, a pretty big part of the appeal of a Nespresso machine is how quickly it can make an espresso-style drink. We used a stopwatch to test the heat-up time, brew time, and frothing time of each machine. We then compared these to the ones listed by the company.Cleanup: After each brew, we marked down any splashes or drips and looked at water reservoir levels. We tried any self-cleaning functions and during long-term testing have descaled machines., Nespresso USA brings luxury coffee and espresso machines straight from the café and into your kitchen. Explore Vertuo and Original machines and premium coffee!, Amazon.com: nespresso machine4 IN 1 Single Serve Coffee Maker with Milk Frother and Coffee Grinder, Coffee Maker for K Cup and Ground Coffee, with 30 oz Removable Water Reservoir, 6 to 14 oz. Brew Sizes, Coffee Machine for Home.