The K1 also has the rubber padding on the front side where the speakers are which is not on the 1st unit.
I mentioned this before, one of my favorite features on the K1 is the ability to adjust the processors power scheme. It can be set per each app. So if you prefer all the processing power to be directed to the aircraft's apps over any others, it can be done.
This is no big deal, but a few days ago I flew my 1st 2 mile (4 mile round trip) flight seen in the video below. The Nvidia's processor preformed great without a glitch. The Nvidia tablet is currently the best android tablet to have for the P3.