I cannot recommend this ZEC miner. Absolutely unstable. I tried it on 6 rigs (all were stable with eth mining), but I have only problems, on some it stopped work in very short time, or hashrate dropped to 0, or it crashed.
If is working hashrate is high, but...
I would recommend - runned it on 16 ethereum rigs ( 280x, 390, 290, 290x cards ) over night and just 2 rigs dropped one card.