I prefer 3Gb versions cause they are cheaper and have smaller ROI time. The hashrate difference is about 5-10% on Equihash, and I'm not sure mining Ethereum on Nvidia is good idea at all.
They are the same only real difference is resale value of the 6gb is higher and can mine ETH longer, but you shouldnt be mining ETH with NVIDIA cards anyway.
Dang.. Why do yall say that lol. I just set up a mini mining rig (2 1050 TIs right now) and am looking to either add more 1050 TIs or go to 1060 3GBs...
I'm currently mining Ethereum right now on SimpleMining OS and using ethpool and claymore-eth-v10.5.