Welcome @draconum! Great to have someone new onboard who's passionate about content and community.
I think you'll like the experience here... you might even find yourself surprised by the ways in which Steemit makes other social platforms seem... less relevant. Sometimes you can achieve a lot more with 200 dedicated readers who engage than with 100,000 random "followers" who don't really care.
You mention tumblr... I'm more of a golden-oldie-moldie... I experience Steemit as the greatest community building site since the heyday of "social blogging" around 2002-2006-- Xanga, LiveJournal, Diary-X and others... a true mix of engaging content and loyal community.