Chromebooks are the simplest computers you can buy today, but they’ve proven a tricky formula for manufacturers to get right. The perfect Chromebook is cheap, fast enough, well-built, and lasts all day long on a single charge. At the other end of the spectrum is the Chromebook Pixel, which offers premium build and fast performance, but costs more than a full-fledged MacBook or Windows Ultrabook. Almost every Windows laptop maker has a Chromebook or two in its lineup, and now Dell is entering the fray.