The new Google Nexus 7 is a big improvement over the original with a bunch of additions like LTE and a super high resolution display – the best in tablets, in fact. And that’s driving a lot of first generation device owners to trade in their old Nexus 7, according to gadget buy-back site Gazelle. There was a 333 percent spike in the number of Nexus 7 tablets traded in compared to the same day last week, for example.