for now 1080ti can roin in two months, i don't know the amd situation but it's not better than nvidia, nvidia is very good at skein and sia, but amd can dual mine sia with ETH, i still think nvidia is better, the 1080ti will hold a good value for gamers, they like strong gpu
1080ti can do the roi in 2 months?? If was like this it has to mine for $400+ per month

it is like that on skein almost $400 per month with that gpu, but it won't last i know, still it should earn $300 easily each month, roi will not be more than 3 months anyway