Immediately after HF 19 was activated, I started a 30 days writing challenge. The goal was to gauge the efforts versus rewards under this new distribution model. I also committed to upsteem at full power at least 3 posts per day. I did this for 27 days (life was a bit demanding this month) distributing, on average, $1.8/post. In total, $145.8 worth of Steem rewards were distributed during this challenge.
What Was The Real Impact Of HF 19?
I confess I had very big expectations in regard to the linear rewards. If you are new here, it's worth knowing that, before HF19 (June 20th, 2017) the distribution from the rewards pool was based on a squared algorithm, meaning, in short, there was a huge gap between minnows and whales. HF 19, code-named "Equality", addressed this by making the votes proportional with the voting power (no squared algorithm).
At the same time, HF 19 introduced a new feature: only 10 votes / day at full power were allowed before the voting power was to be depleted (needing around 2 days to recover completely).
These two changes, combined, created a very interesting paradigm.
1. Self-Voting Was The New Bible
Once people realized their vote is actually meaning something, they started to vote themselves like crazy. That was a very obvious effect of HF19, to such extent that the developers resorted to code hints in order limit this: one release of Condenser, the UI for Steemit, even unchecked the "Upvote post" checkbox which was, until then, checked by default. Some people were a bit baffled, until they realized they need to check that first, and everything returned to normal.
This trend continues now and it's not very conducive to interaction (hence, to growth). But from an economical point of view, it makes sense: there is a natural tendency to maximize profits, so if you can do that by upvoting yourself, if there aren't any strong ethical values there, you will probably do it.
2. Less Voting, More Commenting
In an effort to increase rewards, people started to comment more, hoping to gain more by voting. If you look at some accounts in steem.supply, you will see that some authors on Steemit are just commenting, generating serious revenue.
Unfortunately, this trend created a lot of spam, with meaningless, "follow for follow" comments, which are quite annoying. One way to get rid of these comments, as counterintuitive as it seems, is t just ignore them. They will pile up for a while, until those guys will realize nobody will vote them, and then they'll naturally migrate to other areas.
3. Alliances, Paving The Way For Communities
And that trend opens the way for what I call "alliances". I don't have yet a specific example, but I observed how people started to agglutinate, informally, of course, in what I call "alliances". I will comment on your post, I will upsteem and resteem and then I will see if you do the same. Some small "circles of trust" were created and I agree that my 30 days challenge was one of them. As people got confirmation they are going to be backed up, with votes, resteems, comments or just attention, they kept pushing.
I think "alliances" will soon transform into communities and I intend to be prepared when this will happen. Hence, steem.city.
4. Unexpected Trouble
In an ideal world, all experiments will run in an ideal environment. Alas, we don't live in an idea l world, so things happen. One of these things was the August 1st Bitcoin drama. For a couple of weeks there wasa lot fo turmoil in the crypto world, and Bitcoin plunged to $1800 (while Steem followed suit with $0.8). Luckily, SegWit seems t be locked in (for now, let's see what happens in 3 months) so the price recovered. This plunge certainly affected a few writers, who saw their rewards halving in a matter of days.
To add insult to injury, there was also some intricacy about the reward pool. In short, when HF19 hit, the reward pool wasn't completely drained, so the rewards were bigger than usual. But as new accounts joined in and people were interacting with the blockchain like crazy, the reward pool shrunk very fast, contributing to the decrease in the rewards. As far as I know, the rewards pool is stabilizing now.
The Conclusion?
All in all, I still think HF 19 was a very useful improvement of the Steem blockchain. Unfortunately, code cannot fix human nature, though, it can just make it more obvious.
And that was what happened with this hardfork.
So we're back to square number one, so to speak. There's no code staying in your way now, so just do your best: play nice with other people, give value first, be generous if you want to be treated generously, use sunscreen, don't drink and drive, don't drive and text, you know the drill.
I'm a serial entrepreneur, blogger and ultrarunner. You can find me mainly on my blog at Dragos Roua where I write about productivity, business, relationships and running. Here on Steemit you may stay updated by following me 
https://steemit.com/~witnesses
If you're new to Steemit, you may find these articles relevant (that's also part of my witness activity to support new members of the platform):