Like the XPS 13, Dell expanded its XPS 15 lineup to include a 2-in-1 model. It looks similar to the clamshell one, it has similar hardware inside, and it also has a gorgeous display. Prices are likewise closely matched, and you might be wondering exactly which model is best for you. Let’s break things down to help you make a final decision. The overall look and design of the clamshell XPS 15 lineup hasn’t changed a whole lot over the last few years, sticking with the carbon-fiber inside and CNC-machined aluminum outside. It’s a proven design, and as long as you’re not tired of the look, it should serve you well. The newer 2-in-1 model has taken that classic feel and added two convertible hinges to a thinner and smaller chassis, with the same silver exterior and black interior option; there’s also a brushed onyx color available for the 2-in-1. Both laptops are built extremely well and should put up with a lot of abuse. The backlit chiclet keyboard on the XPS 15 is a delight to use, and the large Precision touchpad on either laptop has plenty of room for multi-touch gestures. It should ultimately come down to a personal test of both laptops, but the X...