lucked out on the last batch of EVGA 3gb from Amazon, all were Samsung.
Rig of 8 avg 200mh/s on claymore for Ethereum.
Is it worth it to look into dual mining?
For the 6gb cards: definitely. Can't speak to the 3gb, but I have 8 of the 6gb (5 Samsung, 3 Hynix) and all 8 take next to no loss in hashrate when dual mining. YMMV of course, but whenever I am mining any ethash coins I ALWAYS dual SIA. Worth a shot...