I had a look at the evolution of my curation rewards over the past 90 days:
For newer steemians, you can do that from https://steemdb.com/@YOURUSERNAME/curation
Hardfork 21 happened on August 27th.
As probably everyone knows, one of the changes that happened on HF21 is that the reward split between author and curators became 50:50, from 75:25 previously.
So, the incentive for curators doubled, from 25% to 50%.
I started curating manually more before that, so I can get into the rhythm.
If you look at the screenshot above, you can see the nice boost in curation rewards from July or early August to present days for my account.
I don't know if they would be the same if I would have chosen to do mostly auto-curation, and optimize on that, but I chose manual curation, and it worked.
Let's see some numbers for comparison, from my account, before and after HF21. Also please note there are way better curators than me out there, without counting the difference in STEEM Power.
To easier see the differences, I chose two periods of 10 days, one before HF21, the other after.
From July 10th to July 20th, before HF21:
The highest reward in SP (calculated at current rates, not historical rates) in the above period was 0.442 SP on July 14th, based on 17 votes, and with an average SP/vote value of ~0.026.
Now let's have a look at recent days, from September 15th to September 25th:
The lowest curation reward was 1.009 SP on September 16th, based on 14 votes and with an average SP/vote of ~0.072. But the lowest SP/vote during the period was on September 24th, with ~0.043 and 28 votes. The highest curation reward sits at almost double that: 1.828 SP, three days ago.
Based on the above observations, the percentage increase between the highest curation reward from the analyzed period before HF21 and the lowest curation reward from the analyzed period after HF21 is 228% in my case!
Higher than one would expect from the doubled curation, but that can be explained by the powerups I did during that period. Also, let's keep in mind I compared the highest reward from before HF21 with the lowest reward from after HF21, not average curation rewards, in which case the percentage increase would be most likely higher.
You can also remark that in the period analyzed before HF21, there is no day with more than 1 SP in curation rewards, while in the period analyzed after HF21, there is no day with less than 1 SP in curation rewards.
In fact, there are days after HF21 when the curation rewards are higher than the author rewards I receive on Steem.
However, my posts got on the radar of the curation team from SmartSteem and a few others big curators in the tribes I write for, and the days my posts are curated by them perform really well. So, on average I do well on the author rewards too after HF21.
I haven't done my monthly stats yet, that's when I'll know pretty much everything that was going on with my account(s) and assets on Steem, but I saw for a while the improvement in curation and wanted to write about it.
If that inspires anyone to do more manual curation, great! Otherwise I can still use it as a sort of public journal entry I can get back to from the future.