Thanks for this comparison, I think it might be useful for some users to post their content in several other platforms but create exclusive content for each platform might be too time consuming and very hard to achieve.
I wonder why do you think of Weku? It is another site similar to Steem.
I might dig into Weku as well, and write another post about it (similar to this one)...
if you do, please find out if they have a blockchain or not......can't tell if they do.