Look out, Razer! Acer is literally and figuratively stretching the definition of Ultrabook with the Aspire Timeline Ultra M3. This 15-inch laptop is the largest and heaviest Ultrabook to date, but at 4.5 pounds, it's still one of the lightest machines with this size screen. More important, it's the first Ultrabook to feature discrete graphics, in this case Nvidia's new GeForce GT640M GPU. Combined with a 256GB SSD, we can easily see mobile gamers gravitating to this system. But just how much oomph do you get for your money?