Understanding Comment Payouts

I'd been searching high and low for information about how SteemIt pays out comments. But everytime I searched the topic, I only found information about upvoting. I was getting pretty frustrated, but I kept searching.

elements source 1, source 2, source 3

I finally found this post by @benjmiller, "How Comments Are Paid Out" from last year. According to @benjmiller, and in turn according to SteemIt's White Paper from May 2016, 50% for a thread (post) goes to comments in the form of Steem Power and Steem Dollars. But according to the comments in @benjmiller's post, the payouts for comments have been changed to 25% of the payouts for a given post.

So, what is the most current information? And how do the payouts for comments break down? Does the first commenter get the highest percentage, or is all based on upvoting?

source 1, source 2, source 3

I've looked high and low, been lost in the weeds of general curation payouts - and totally forgot that I was looking for information on comment curation rewards.

https://steemit.com/steemit/@shenanigator/updated-steemit-faq-part-4-payouts
https://steemit.com/steemit/@shenanigator/the-ultimate-guide-to-steemit-payouts
https://steemit.com/@theoretical
https://steemit.com/curation/@onetree/curation-strategy-of-a-minnow
https://steemit.com/steemit/@calamus056/how-to-improve-your-curation-quality

And now for my ultimate conclusion. Based on incomplete information, @shenanigator seems to have provided me with the most useful answer. According to his post "The Ultimate Guide To Steemit Payouts," comment payouts come from upvoting of the actual comments. Apparently, there is some form of algorithm that is similar to rewarding upvotes on original posts. I am trying to figure out if those rewards are of part of the payout of the original post - I would assume so.

So, long story short, I am still confused. But I do think that comments are rewarded in a similar fashion to original posts.