Up ’til now, the Surface has been stuck in a weird limbo between tablet and laptop. No more. The Microsoft Surface Book is designed to be a killer laptop and a killer tablet. Its unique hinge lets you detach the screen from the keyboard, turning it into a tablet, and reattach the screen facing out, letting you take advantage of the powerful, MacBook Pro-besting processor, RAM, and graphics built into the keyboard base without giving up the highly responsive, pressure-sensitive stylus and finger-ready touch surface. You can also pair it with a Surface Dock for desktop use, but even if you don’t, it’s the most interesting device that we’ve seen out of Redmond in, well, ever.