Originally Posted by l_macd
Early indications indicate there is one other change, quality control of the screens!
Yeah they are exactly same except Amazon has probably switched manufacturers or something like that for screen quality. Also the back on the K4B has a different finish. It the same backing as the Kindle Fire now making it way easier to hold with one hand. No more slippage but you now have to worry about staining the back from the oil on your hands.
My K4S is stained on the back from my cover. It looks ugly.