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.