What is the motivation of this change? From the user's perspective, it seems illogical.
It makes bot / automated votes > users organic votes. No user can compete with bots and put vote early enough to get good curation reward.
Currently, the best reward is when we vote, say, between 5 and 10 minutes. I don't think it is currently a big deal with users voting too early then and "losing" curation reward.
I've read post from forum and this sentence below is definitely not true:
(...), they just lose curation by voting earlier than 15 mins.
They may lose, they may gain. It all depends. It depends on sum of rshares before our vote, sum of rshares of our vote, time of vote and total sum of rshares after payout. But for most users in most cases the best time to vote is between 5-10. And the smaller the vote the more profitable is to vote earlier. On the other hand whales should vote at the end of the curation window.
To give a better picture, it may look like this.