Since Oct 28, 2016. Initially I had only 10 Sol/s as the solve rate cost was pretty high at that time. But, they have radically slashed their solve rate cost since the announcement of Equihash FPGA. Now, I have bought a LOT and heavily invested into Zcash mining.

Interestingly, Zcash price is also stabilizing, which is a sign of maturity - http://www.coindesk.com/zcrash-zcashs-price-finding-floor/