yea, go amd if your planning to mine just ETH but in my opinion 1070s a good buy for more versatile/flexible gpu
Sorry not aware that AMD is better for ETH. but for future use 1070 is better than 1060? for AMD part which is better to purchase?
I prefer 1070 for its flexibility. But if you focus on ETH, P106-100 is a good choice for better ROI.
I'm using P106-100 for mining ETH, each card costs about 240$ here, and it could draw 25.5 Mh/s, while 1070 may cost about 470$ and hash 30.5 Mh/s.
If you do really want to save up I would really choose P106-100 because its cheaper and the price difference is too big when you tend to buy 1070 on just mining ETH. This is only on case to case basis but if you do have plans on mining other alts then I would go for 1070 because it is better on 1060 performance but as expected roi would be longer considering on the cost.