One video doesn't really determine the worth of a product. Testing with millions of malware samples, of different kinds, origins, and varieties, however, can give you a more accurate view of how the product will perform on a day-to-day basis. By default, KIS asks the user about "suspicious files" instead of just deleting them, which can sometimes be a bit too much for the average user. I've been using KIS for about a week or two now, and it's slowed down my computer/gaming a bit more than Avast did in the past, but it's detection rate has been good so far.
To answer the question you're asking, I would say KIS Final is better, because NIS is still in beta. Assuming Symantec keeps up their history of good, light products, I would choose NIS over KIS because of its lightness and overall better user interface (i.e settings, popups).