Ultra Humanite, great villain or greatest villain?
Well, as unpopular as this might be received, I'm with the Byrne's version of Ultra and Luthor amalgam. However, if I had my druthers, actually, I'd have preferred Ultra to be the science guy and Lex more along Wolfman's version.
Although the science looks great in books, hyper-intelligent and strategic human would make for some great stories. Keeping them separate would make for some interesting team-up battles. But ultimately (no pun intended) Lex became the super-science guy and Ultra was phased out.
True Golden Age Supes is always a treat to read. If you notice in the K-Metal story, people are in fear around Superman, which there was an extensive thread on this earlier. That story was completed around mid to late-1940. So that demonstrates "Superman=fear" to be somewhat status quo as late as then. But, there again, in the early GA stories, I think a lot of what you're seeing is the joy of Siegel asserting his own wishful thinking through his character on what he'd like to do to handle societal ills.
The history I've been piecing together while working on K-Metal was just mainly due to his and Shuster's shop having trouble keeping up with the demand of the character, more and more, Supes became the expression of the publisher than his creators - hence the more Abe Lincoln-esque personality developments Supes later assumes.
Where would Superman be if Shuster and Siegel continued to hold onto the production and writing? I would hypothosize we'd have lost him to Captain Marvel by the mid to late 40's. I'm sincerely doubting National would be so keen to have legal battles with Fawcett if National never brought Supes in house, and it was mainly one crazy Mr. Wertman's relatively successful attack on comics, combined with the pressing legal issues that caused Fawcett to give up the Cap'n Marvel ghost.