How are you getting 70MB read speeds from the sdcard slot? it doesn't support UHS-1 speeds.. The most you will get is around 18MB read.
Seems about right, I just got about 19MB per second on a benchmark. Still seems fast enough to prevent any slowdown in games though.
Well done Samsung.
you cant see it anywhere else, but it seems anything around 50% grey is where the smearing is the most obvious. It can be stopped almost entirely by using screen adjuster but that means having something else running constantly. Hopefully Samsung will get it right soon