Bitmain now controls ~50% of mined coins

https://steemit.com/cryptocurrency/@nastypaperclip/more-than-50-of-the-blocks-in-zcash-produce-only-three-addresses

It's not a good idea to stick with zcash. Many zcash forks already switched to  Zhash  algo, I believe VoteCoin also should take a look to it.