It's good to vote for 30 witnesses, because a lot of them are trying and we have to support them, I already found a list of the best 30 witnesses and voted for them but I try to update the list every 2-3 months. Here is the list with details : https://steemit.com/witness-category/@clixmoney/it-s-the-time-to-vote-for-the-right-witnesses ( The post writen 4 months ago ).