I did a post about my curation rewards recently and someone left a link in the comments to a post with visual representation of how curation rewards are split. @miniature-tiger was the one who created the post, I believe and @yabapmatt shared it with me.

But yes you're right there's a lot of factors and I've found I get the best curation rewards when I vote for authors who are earning $1-10 per post or sometimes more, but the key is if I have more steem power and vote earlier than most of the others, I get the lions share of the curation reward split. I'm still playing around with the timing but I've also found that about 16-25 minutes is a good timing range to cast a vote.

My 100% vote is worth around 50 cents and I once got a 0.48 SP curation reward which was pretty shocking....I definitely got the majority of that 25%!

On a separate note, I don't think I've cast a witness vote for you yet..I didn't realize you were a witness. I've got like 3 votes left and one of them will be yours here in a minute.