I am conjecturing that the Samsung variant gets better Hash Rates, just like the normal 470s.
And also assuming that the 8GB variant will last longer for mining. Memory seems to be an issue when block size goes up for Eth, at least at an earlier period it was.
Agree on the 8gb but it's also true that with Casper PoS will be out so no more mining for ETH.... which will send all of us to ETC considering it is the second best return... and the difficulty is quite low... so again... maybe those extra dollars saved for the 4gb are going to be a good turning point...