The Acer C720-2420 Chromebook is the successor of the Acer C710 and comes with several improvements. The most notable one for me is the vastly improved battery life of up to 8.5 hours. With 2.76 lbs it also weighs slightly less, so certainly better mobility with this model.

Apart from the CPU the rest of the hardware specs don't differ too much: Intel Celeron 2955U 1.4 GHz (Haswell micro-architecture), 2 DDR3L SDRAM, 32 GB Solid-State Drive, 11.6" anti-glare screen, Intel HD graphics, 1x USB 3.0, 1x USB 2.0, 1x HDMI™, full-size Acer FineTip keyboard, and multi-gesture touchpad.