Which one is best for mining?
No doubts the 1080ti,
Seems its better to get a 1070 for mining than a 1080
1070Ti is also better than 1070.
A 1070Ti is actually better overall than a 1080.
Agreed... my 1070Ti systems earn about the same as my 1080 systems and cost less (using algo switching setup).
Maybe buying a premium 1080 card you could beat the 1070Ti but then at even more cost.
If you use the Enlargement software to increase the memory efficiency, the 1080Ti is also very good.