Till now GTX 1070/1080 are disappointing for monero (around 600-700 h/s) against 850-880 for nano or fury-x. This could change if sp release the somewhat promised new cryptonight miner with 900h/s for a GTX 1070.
More like 700/730 for 1070, but the consumption are far lower than with nano or fury. But yeah we need a better one, so far nvidia is much more profitable mining zcash or lbry than monero even @900h, i think that's why the improved monero miner isn't here.
The 1080 is the best for ZEC.