FWIW, I am inclined to think that "rationality" is a bad brand identification for a good thing. Rationality conjures up "Spock" (the Star Trek character) not "Spock" (the compassionate and wise child rearing guru). It puts an emphasis on a very inhuman part of the kind of human being you feel you are becoming.

Whatever it means in your context, as a brand to evangelize to others about its benefits, it is lacking. Better, in the sense of offering a positive vision, perhaps than "atheism" or "secularism" but not still not grounded and humane enough. I like "naturalist" better, although it is loaded with the connotation of bird watching, and also "humanist" although the term, without the modifier "secular" can mean little more than someone who gives a damn. "Enlightened" (as in the Enlightenment era) might be a good term if it weren't so damned arrogant in the modern vernacular.

The sense that I think you are trying to capture of something of the sense conveyed by the title to Carl Sagan's book "Demon Haunted World." You want to convey the joys of having exorcised the demons and opening yourself to seeing the world more clearly. But, to sell it to others, I think it is necessary to find a better marketing plan.